Chemical Quantities

The Mole

But firsthellipBut firsthellip1 CuCl2

2 Na3PO4

3 S2O5

4 PbSO4∙2H2O

5 HNO2

6 Silver acetate7 Gold (III) iodide

8 Dinitrogen tetrabromide9 Cuprous nitrate tetrahydrate

10 Hydrofluoric acid

AnswersAnswers1 Copper (II) chloride or cupric chloride

2 Sodium phosphate3 Dinitrogen pentoxide

4 Lead (II) sulfate dihydrate or plumbous sulfate dihydrate

5 Nitrous acid6 Ag2C2H3O2

7 AuI38 N2Br4

9 Cu(NO2)2 ∙ 4H2O

10 HF

Pick out the mistake and

write it down in your noteshellipdo not say it out loud or in a

whisper or in sign language or in any way that would let someone else

know the answer before

they could figure it out on

their own

And secondhellipAnd secondhellipThe portfoliohellipSectionsNotesmdashdate each day chronological order

and not kept in a spiral notebookHWmdashdated and put in chronological orderQuestsmdashsee HWTestsmdashsee HWGeneralmdasheverything that doesnrsquot have a

home in the first set of sections goes here

Daily Journalhellip

The Daily JournalThe Daily Journal1 A statement of what was done that day (We

took notes over moles and Avogadrorsquos number)

2 A summary of your notes Explain in detail in your own words what was covered in the

notes for that day Or explain what the purpose of the lab was etc

3 A couple statements about what you do not clearly understand or what you could not

clearly describe in part 2 above4 What you are doing that night or what you

have already done that night concerning this class

ReadyReadyNow we can begin with noteshellip

Goals for Learning

bull To convert between moles and number of particlesbull To convert between mass and molesbull To convert between moles and gas volume at STPbull To use molarity in conversions involving solutionsbull To calculate the percent composition of a compoundbull To find an empirical formula from percent compositionbull To use an empirical formula to find a molecular formula

Organization of UnitVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Objectives

bull Explain what a mole isbull Convert between moles and number of particlesbull Define molar massbull Find the molar mass of an element using the

periodic tablebull Calculate the molar mass of a compoundbull Use molar mass to convert between mass and

moles

Key Terms

bull Mole (mol)bull Avogadrorsquos numberbull Atomic massbull Molar mass

Measuring Matter

bull All matter is made of different kinds of particlesbull These particles can be molecules atoms or ionsbull Elements such as helium and iron exist as single

atomsbull Other elements like H O and N are diatomic

moleculesbull Molecular compounds like CO2 and water also exist

as molecules

Measuring Matter

bull Ionic compounds like ammonium carbonate consist of cations and anions in formula units

bull Depending on the substance different names for the particles are used

bull In this unit all atoms molecules and formula units are referred to as particles

The Mole bull The particles in matter are very very smallmdashtoo small to

see even with a microscopebull Counting the number of particles in a sample is not

possible bull Instead of counting them chemists measure the number

of particles with a unit called the molebull The abbreviation for mole is mol (I suppose there is a

logical reason for this)bull The mole is a unit for measuring the amount of substance

The Mole bull The word mole means a number similar to the

word dozenbull 1 dozen eggs = 12 eggsbull 1 mole eggs = 6022 x 1023 eggsbull One mole of any substance contains 6022 x 1023

particlesbull These particles can be atoms molecules or

formula units

The Mole bull The number 6022 x 1023 is called Avogadrorsquos numberbull It is a very very large numberbull A mole of eggs is more eggs than have ever been eaten

in the history of the worldbull If you stacked a 6022 x 1023 sheets of paper the pile

would reach to the sun and back more than a million times

bull However a mole of molecules atoms and formula units is not very big

TodayhellipTodayhellip

bull Get ready for practicehellipbull Notes to fill in the flow chart from

Fridaybull Journalsmdashin classmdash5 minutes before

the bellmdashyou must write the entire timehellip

Time to Practice 1 NiCl22 K3PO4

3 S2Cl24 H2CO3

5 Cu(NO3)2

6 Sodium hypochlorite7 Silver bromide8 Hydrochloric acid9 Strontium permanganate10 Sulfur trioxide

Time to Practice 1 Nickel (II) chloride or nickelous chloride or 23 chloride

2 Potassium phosphate3 Disulfur dichlorine4 Hydrocarbonic acid

5 Copper (II) nitrate or Cupric nitrate6 NaClO7 AgBr8 HCl

9 Sr(MnO4)2

10 SO3

Time to Recall 1 What is the date of Mole Day2 What time does it begin End3 Write down the food you will be bringing in on Mole

Day4 If you had a mole of bananas how many bananas

would you have5 What is this called (Name of dude)

Mole-Particle ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use Avogadrorsquos

of 1 mole = 6022 X 1023

particles

Mole-Particle Conversions bull Chemists use Avogadrorsquos number to calculate the

number of particles in a sample of matterbull Suppose you are told that balloon contains 200 mol of

the gas argonndashand nothing elsebull You want to know how many particles are in the

balloonbull You want to change the measurement units from moles

to particlesbull Moles Ar particles Ar

Mole-Particle Conversions bull Your conversion factor is 1 mol Ar = 6022 x 1023

particles Arbull Write the given number and unit Include the chemical

symbol or formula of the substancebull Set up a factor label gridbull Use the conversion factor in the gridmdashmaking sure to

align units so that they will cancelbull Give the answer with the correct unit and the correct

number of significant digits

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

But firsthellipBut firsthellip1 CuCl2

2 Na3PO4

3 S2O5

4 PbSO4∙2H2O

5 HNO2

6 Silver acetate7 Gold (III) iodide

8 Dinitrogen tetrabromide9 Cuprous nitrate tetrahydrate

10 Hydrofluoric acid

AnswersAnswers1 Copper (II) chloride or cupric chloride

2 Sodium phosphate3 Dinitrogen pentoxide

4 Lead (II) sulfate dihydrate or plumbous sulfate dihydrate

5 Nitrous acid6 Ag2C2H3O2

7 AuI38 N2Br4

9 Cu(NO2)2 ∙ 4H2O

10 HF

Pick out the mistake and

write it down in your noteshellipdo not say it out loud or in a

whisper or in sign language or in any way that would let someone else

know the answer before

they could figure it out on

their own

And secondhellipAnd secondhellipThe portfoliohellipSectionsNotesmdashdate each day chronological order

and not kept in a spiral notebookHWmdashdated and put in chronological orderQuestsmdashsee HWTestsmdashsee HWGeneralmdasheverything that doesnrsquot have a

home in the first set of sections goes here

Daily Journalhellip

The Daily JournalThe Daily Journal1 A statement of what was done that day (We

took notes over moles and Avogadrorsquos number)

2 A summary of your notes Explain in detail in your own words what was covered in the

notes for that day Or explain what the purpose of the lab was etc

3 A couple statements about what you do not clearly understand or what you could not

clearly describe in part 2 above4 What you are doing that night or what you

have already done that night concerning this class

ReadyReadyNow we can begin with noteshellip

Goals for Learning

bull To convert between moles and number of particlesbull To convert between mass and molesbull To convert between moles and gas volume at STPbull To use molarity in conversions involving solutionsbull To calculate the percent composition of a compoundbull To find an empirical formula from percent compositionbull To use an empirical formula to find a molecular formula

Organization of UnitVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Objectives

bull Explain what a mole isbull Convert between moles and number of particlesbull Define molar massbull Find the molar mass of an element using the

periodic tablebull Calculate the molar mass of a compoundbull Use molar mass to convert between mass and

moles

Key Terms

bull Mole (mol)bull Avogadrorsquos numberbull Atomic massbull Molar mass

Measuring Matter

bull All matter is made of different kinds of particlesbull These particles can be molecules atoms or ionsbull Elements such as helium and iron exist as single

atomsbull Other elements like H O and N are diatomic

moleculesbull Molecular compounds like CO2 and water also exist

as molecules

Measuring Matter

bull Ionic compounds like ammonium carbonate consist of cations and anions in formula units

bull Depending on the substance different names for the particles are used

bull In this unit all atoms molecules and formula units are referred to as particles

The Mole bull The particles in matter are very very smallmdashtoo small to

see even with a microscopebull Counting the number of particles in a sample is not

possible bull Instead of counting them chemists measure the number

of particles with a unit called the molebull The abbreviation for mole is mol (I suppose there is a

logical reason for this)bull The mole is a unit for measuring the amount of substance

The Mole bull The word mole means a number similar to the

word dozenbull 1 dozen eggs = 12 eggsbull 1 mole eggs = 6022 x 1023 eggsbull One mole of any substance contains 6022 x 1023

particlesbull These particles can be atoms molecules or

formula units

The Mole bull The number 6022 x 1023 is called Avogadrorsquos numberbull It is a very very large numberbull A mole of eggs is more eggs than have ever been eaten

in the history of the worldbull If you stacked a 6022 x 1023 sheets of paper the pile

would reach to the sun and back more than a million times

bull However a mole of molecules atoms and formula units is not very big

TodayhellipTodayhellip

bull Get ready for practicehellipbull Notes to fill in the flow chart from

Fridaybull Journalsmdashin classmdash5 minutes before

the bellmdashyou must write the entire timehellip

Time to Practice 1 NiCl22 K3PO4

3 S2Cl24 H2CO3

5 Cu(NO3)2

6 Sodium hypochlorite7 Silver bromide8 Hydrochloric acid9 Strontium permanganate10 Sulfur trioxide

Time to Practice 1 Nickel (II) chloride or nickelous chloride or 23 chloride

2 Potassium phosphate3 Disulfur dichlorine4 Hydrocarbonic acid

5 Copper (II) nitrate or Cupric nitrate6 NaClO7 AgBr8 HCl

9 Sr(MnO4)2

10 SO3

Time to Recall 1 What is the date of Mole Day2 What time does it begin End3 Write down the food you will be bringing in on Mole

Day4 If you had a mole of bananas how many bananas

would you have5 What is this called (Name of dude)

Mole-Particle ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use Avogadrorsquos

of 1 mole = 6022 X 1023

particles

Mole-Particle Conversions bull Chemists use Avogadrorsquos number to calculate the

number of particles in a sample of matterbull Suppose you are told that balloon contains 200 mol of

the gas argonndashand nothing elsebull You want to know how many particles are in the

balloonbull You want to change the measurement units from moles

to particlesbull Moles Ar particles Ar

Mole-Particle Conversions bull Your conversion factor is 1 mol Ar = 6022 x 1023

particles Arbull Write the given number and unit Include the chemical

symbol or formula of the substancebull Set up a factor label gridbull Use the conversion factor in the gridmdashmaking sure to

align units so that they will cancelbull Give the answer with the correct unit and the correct

number of significant digits

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

AnswersAnswers1 Copper (II) chloride or cupric chloride

2 Sodium phosphate3 Dinitrogen pentoxide

4 Lead (II) sulfate dihydrate or plumbous sulfate dihydrate

5 Nitrous acid6 Ag2C2H3O2

7 AuI38 N2Br4

9 Cu(NO2)2 ∙ 4H2O

10 HF

Pick out the mistake and

write it down in your noteshellipdo not say it out loud or in a

whisper or in sign language or in any way that would let someone else

know the answer before

they could figure it out on

their own

And secondhellipAnd secondhellipThe portfoliohellipSectionsNotesmdashdate each day chronological order

and not kept in a spiral notebookHWmdashdated and put in chronological orderQuestsmdashsee HWTestsmdashsee HWGeneralmdasheverything that doesnrsquot have a

home in the first set of sections goes here

Daily Journalhellip

The Daily JournalThe Daily Journal1 A statement of what was done that day (We

took notes over moles and Avogadrorsquos number)

2 A summary of your notes Explain in detail in your own words what was covered in the

notes for that day Or explain what the purpose of the lab was etc

3 A couple statements about what you do not clearly understand or what you could not

clearly describe in part 2 above4 What you are doing that night or what you

have already done that night concerning this class

ReadyReadyNow we can begin with noteshellip

Goals for Learning

bull To convert between moles and number of particlesbull To convert between mass and molesbull To convert between moles and gas volume at STPbull To use molarity in conversions involving solutionsbull To calculate the percent composition of a compoundbull To find an empirical formula from percent compositionbull To use an empirical formula to find a molecular formula

Organization of UnitVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Objectives

bull Explain what a mole isbull Convert between moles and number of particlesbull Define molar massbull Find the molar mass of an element using the

periodic tablebull Calculate the molar mass of a compoundbull Use molar mass to convert between mass and

moles

Key Terms

bull Mole (mol)bull Avogadrorsquos numberbull Atomic massbull Molar mass

Measuring Matter

bull All matter is made of different kinds of particlesbull These particles can be molecules atoms or ionsbull Elements such as helium and iron exist as single

atomsbull Other elements like H O and N are diatomic

moleculesbull Molecular compounds like CO2 and water also exist

as molecules

Measuring Matter

bull Ionic compounds like ammonium carbonate consist of cations and anions in formula units

bull Depending on the substance different names for the particles are used

bull In this unit all atoms molecules and formula units are referred to as particles

The Mole bull The particles in matter are very very smallmdashtoo small to

see even with a microscopebull Counting the number of particles in a sample is not

possible bull Instead of counting them chemists measure the number

of particles with a unit called the molebull The abbreviation for mole is mol (I suppose there is a

logical reason for this)bull The mole is a unit for measuring the amount of substance

The Mole bull The word mole means a number similar to the

word dozenbull 1 dozen eggs = 12 eggsbull 1 mole eggs = 6022 x 1023 eggsbull One mole of any substance contains 6022 x 1023

particlesbull These particles can be atoms molecules or

formula units

The Mole bull The number 6022 x 1023 is called Avogadrorsquos numberbull It is a very very large numberbull A mole of eggs is more eggs than have ever been eaten

in the history of the worldbull If you stacked a 6022 x 1023 sheets of paper the pile

would reach to the sun and back more than a million times

bull However a mole of molecules atoms and formula units is not very big

TodayhellipTodayhellip

bull Get ready for practicehellipbull Notes to fill in the flow chart from

Fridaybull Journalsmdashin classmdash5 minutes before

the bellmdashyou must write the entire timehellip

Time to Practice 1 NiCl22 K3PO4

3 S2Cl24 H2CO3

5 Cu(NO3)2

6 Sodium hypochlorite7 Silver bromide8 Hydrochloric acid9 Strontium permanganate10 Sulfur trioxide

Time to Practice 1 Nickel (II) chloride or nickelous chloride or 23 chloride

2 Potassium phosphate3 Disulfur dichlorine4 Hydrocarbonic acid

5 Copper (II) nitrate or Cupric nitrate6 NaClO7 AgBr8 HCl

9 Sr(MnO4)2

10 SO3

Time to Recall 1 What is the date of Mole Day2 What time does it begin End3 Write down the food you will be bringing in on Mole

Day4 If you had a mole of bananas how many bananas

would you have5 What is this called (Name of dude)

Mole-Particle ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use Avogadrorsquos

of 1 mole = 6022 X 1023

particles

Mole-Particle Conversions bull Chemists use Avogadrorsquos number to calculate the

number of particles in a sample of matterbull Suppose you are told that balloon contains 200 mol of

the gas argonndashand nothing elsebull You want to know how many particles are in the

balloonbull You want to change the measurement units from moles

to particlesbull Moles Ar particles Ar

Mole-Particle Conversions bull Your conversion factor is 1 mol Ar = 6022 x 1023

particles Arbull Write the given number and unit Include the chemical

symbol or formula of the substancebull Set up a factor label gridbull Use the conversion factor in the gridmdashmaking sure to

align units so that they will cancelbull Give the answer with the correct unit and the correct

number of significant digits

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

And secondhellipAnd secondhellipThe portfoliohellipSectionsNotesmdashdate each day chronological order

and not kept in a spiral notebookHWmdashdated and put in chronological orderQuestsmdashsee HWTestsmdashsee HWGeneralmdasheverything that doesnrsquot have a

home in the first set of sections goes here

Daily Journalhellip

The Daily JournalThe Daily Journal1 A statement of what was done that day (We

took notes over moles and Avogadrorsquos number)

2 A summary of your notes Explain in detail in your own words what was covered in the

notes for that day Or explain what the purpose of the lab was etc

3 A couple statements about what you do not clearly understand or what you could not

clearly describe in part 2 above4 What you are doing that night or what you

have already done that night concerning this class

ReadyReadyNow we can begin with noteshellip

Goals for Learning

bull To convert between moles and number of particlesbull To convert between mass and molesbull To convert between moles and gas volume at STPbull To use molarity in conversions involving solutionsbull To calculate the percent composition of a compoundbull To find an empirical formula from percent compositionbull To use an empirical formula to find a molecular formula

Organization of UnitVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Objectives

bull Explain what a mole isbull Convert between moles and number of particlesbull Define molar massbull Find the molar mass of an element using the

periodic tablebull Calculate the molar mass of a compoundbull Use molar mass to convert between mass and

moles

Key Terms

bull Mole (mol)bull Avogadrorsquos numberbull Atomic massbull Molar mass

Measuring Matter

bull All matter is made of different kinds of particlesbull These particles can be molecules atoms or ionsbull Elements such as helium and iron exist as single

atomsbull Other elements like H O and N are diatomic

moleculesbull Molecular compounds like CO2 and water also exist

as molecules

Measuring Matter

bull Ionic compounds like ammonium carbonate consist of cations and anions in formula units

bull Depending on the substance different names for the particles are used

bull In this unit all atoms molecules and formula units are referred to as particles

The Mole bull The particles in matter are very very smallmdashtoo small to

see even with a microscopebull Counting the number of particles in a sample is not

possible bull Instead of counting them chemists measure the number

of particles with a unit called the molebull The abbreviation for mole is mol (I suppose there is a

logical reason for this)bull The mole is a unit for measuring the amount of substance

The Mole bull The word mole means a number similar to the

word dozenbull 1 dozen eggs = 12 eggsbull 1 mole eggs = 6022 x 1023 eggsbull One mole of any substance contains 6022 x 1023

particlesbull These particles can be atoms molecules or

formula units

The Mole bull The number 6022 x 1023 is called Avogadrorsquos numberbull It is a very very large numberbull A mole of eggs is more eggs than have ever been eaten

in the history of the worldbull If you stacked a 6022 x 1023 sheets of paper the pile

would reach to the sun and back more than a million times

bull However a mole of molecules atoms and formula units is not very big

TodayhellipTodayhellip

bull Get ready for practicehellipbull Notes to fill in the flow chart from

Fridaybull Journalsmdashin classmdash5 minutes before

the bellmdashyou must write the entire timehellip

Time to Practice 1 NiCl22 K3PO4

3 S2Cl24 H2CO3

5 Cu(NO3)2

6 Sodium hypochlorite7 Silver bromide8 Hydrochloric acid9 Strontium permanganate10 Sulfur trioxide

Time to Practice 1 Nickel (II) chloride or nickelous chloride or 23 chloride

2 Potassium phosphate3 Disulfur dichlorine4 Hydrocarbonic acid

5 Copper (II) nitrate or Cupric nitrate6 NaClO7 AgBr8 HCl

9 Sr(MnO4)2

10 SO3

Time to Recall 1 What is the date of Mole Day2 What time does it begin End3 Write down the food you will be bringing in on Mole

Day4 If you had a mole of bananas how many bananas

would you have5 What is this called (Name of dude)

Mole-Particle ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use Avogadrorsquos

of 1 mole = 6022 X 1023

particles

Mole-Particle Conversions bull Chemists use Avogadrorsquos number to calculate the

number of particles in a sample of matterbull Suppose you are told that balloon contains 200 mol of

the gas argonndashand nothing elsebull You want to know how many particles are in the

balloonbull You want to change the measurement units from moles

to particlesbull Moles Ar particles Ar

Mole-Particle Conversions bull Your conversion factor is 1 mol Ar = 6022 x 1023

particles Arbull Write the given number and unit Include the chemical

symbol or formula of the substancebull Set up a factor label gridbull Use the conversion factor in the gridmdashmaking sure to

align units so that they will cancelbull Give the answer with the correct unit and the correct

number of significant digits

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

The Daily JournalThe Daily Journal1 A statement of what was done that day (We

took notes over moles and Avogadrorsquos number)

2 A summary of your notes Explain in detail in your own words what was covered in the

notes for that day Or explain what the purpose of the lab was etc

3 A couple statements about what you do not clearly understand or what you could not

clearly describe in part 2 above4 What you are doing that night or what you

have already done that night concerning this class

ReadyReadyNow we can begin with noteshellip

Goals for Learning

bull To convert between moles and number of particlesbull To convert between mass and molesbull To convert between moles and gas volume at STPbull To use molarity in conversions involving solutionsbull To calculate the percent composition of a compoundbull To find an empirical formula from percent compositionbull To use an empirical formula to find a molecular formula

Organization of UnitVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Objectives

bull Explain what a mole isbull Convert between moles and number of particlesbull Define molar massbull Find the molar mass of an element using the

periodic tablebull Calculate the molar mass of a compoundbull Use molar mass to convert between mass and

moles

Key Terms

bull Mole (mol)bull Avogadrorsquos numberbull Atomic massbull Molar mass

Measuring Matter

bull All matter is made of different kinds of particlesbull These particles can be molecules atoms or ionsbull Elements such as helium and iron exist as single

atomsbull Other elements like H O and N are diatomic

moleculesbull Molecular compounds like CO2 and water also exist

as molecules

Measuring Matter

bull Ionic compounds like ammonium carbonate consist of cations and anions in formula units

bull Depending on the substance different names for the particles are used

bull In this unit all atoms molecules and formula units are referred to as particles

The Mole bull The particles in matter are very very smallmdashtoo small to

see even with a microscopebull Counting the number of particles in a sample is not

possible bull Instead of counting them chemists measure the number

of particles with a unit called the molebull The abbreviation for mole is mol (I suppose there is a

logical reason for this)bull The mole is a unit for measuring the amount of substance

The Mole bull The word mole means a number similar to the

word dozenbull 1 dozen eggs = 12 eggsbull 1 mole eggs = 6022 x 1023 eggsbull One mole of any substance contains 6022 x 1023

particlesbull These particles can be atoms molecules or

formula units

The Mole bull The number 6022 x 1023 is called Avogadrorsquos numberbull It is a very very large numberbull A mole of eggs is more eggs than have ever been eaten

in the history of the worldbull If you stacked a 6022 x 1023 sheets of paper the pile

would reach to the sun and back more than a million times

bull However a mole of molecules atoms and formula units is not very big

TodayhellipTodayhellip

bull Get ready for practicehellipbull Notes to fill in the flow chart from

Fridaybull Journalsmdashin classmdash5 minutes before

the bellmdashyou must write the entire timehellip

Time to Practice 1 NiCl22 K3PO4

3 S2Cl24 H2CO3

5 Cu(NO3)2

6 Sodium hypochlorite7 Silver bromide8 Hydrochloric acid9 Strontium permanganate10 Sulfur trioxide

Time to Practice 1 Nickel (II) chloride or nickelous chloride or 23 chloride

2 Potassium phosphate3 Disulfur dichlorine4 Hydrocarbonic acid

5 Copper (II) nitrate or Cupric nitrate6 NaClO7 AgBr8 HCl

9 Sr(MnO4)2

10 SO3

Time to Recall 1 What is the date of Mole Day2 What time does it begin End3 Write down the food you will be bringing in on Mole

Day4 If you had a mole of bananas how many bananas

would you have5 What is this called (Name of dude)

Mole-Particle ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use Avogadrorsquos

of 1 mole = 6022 X 1023

particles

Mole-Particle Conversions bull Chemists use Avogadrorsquos number to calculate the

number of particles in a sample of matterbull Suppose you are told that balloon contains 200 mol of

the gas argonndashand nothing elsebull You want to know how many particles are in the

balloonbull You want to change the measurement units from moles

to particlesbull Moles Ar particles Ar

Mole-Particle Conversions bull Your conversion factor is 1 mol Ar = 6022 x 1023

particles Arbull Write the given number and unit Include the chemical

symbol or formula of the substancebull Set up a factor label gridbull Use the conversion factor in the gridmdashmaking sure to

align units so that they will cancelbull Give the answer with the correct unit and the correct

number of significant digits

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

ReadyReadyNow we can begin with noteshellip

Goals for Learning

bull To convert between moles and number of particlesbull To convert between mass and molesbull To convert between moles and gas volume at STPbull To use molarity in conversions involving solutionsbull To calculate the percent composition of a compoundbull To find an empirical formula from percent compositionbull To use an empirical formula to find a molecular formula

Organization of UnitVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Objectives

bull Explain what a mole isbull Convert between moles and number of particlesbull Define molar massbull Find the molar mass of an element using the

periodic tablebull Calculate the molar mass of a compoundbull Use molar mass to convert between mass and

moles

Key Terms

bull Mole (mol)bull Avogadrorsquos numberbull Atomic massbull Molar mass

Measuring Matter

bull All matter is made of different kinds of particlesbull These particles can be molecules atoms or ionsbull Elements such as helium and iron exist as single

atomsbull Other elements like H O and N are diatomic

moleculesbull Molecular compounds like CO2 and water also exist

as molecules

Measuring Matter

bull Ionic compounds like ammonium carbonate consist of cations and anions in formula units

bull Depending on the substance different names for the particles are used

bull In this unit all atoms molecules and formula units are referred to as particles

The Mole bull The particles in matter are very very smallmdashtoo small to

see even with a microscopebull Counting the number of particles in a sample is not

possible bull Instead of counting them chemists measure the number

of particles with a unit called the molebull The abbreviation for mole is mol (I suppose there is a

logical reason for this)bull The mole is a unit for measuring the amount of substance

The Mole bull The word mole means a number similar to the

word dozenbull 1 dozen eggs = 12 eggsbull 1 mole eggs = 6022 x 1023 eggsbull One mole of any substance contains 6022 x 1023

particlesbull These particles can be atoms molecules or

formula units

The Mole bull The number 6022 x 1023 is called Avogadrorsquos numberbull It is a very very large numberbull A mole of eggs is more eggs than have ever been eaten

in the history of the worldbull If you stacked a 6022 x 1023 sheets of paper the pile

would reach to the sun and back more than a million times

bull However a mole of molecules atoms and formula units is not very big

TodayhellipTodayhellip

bull Get ready for practicehellipbull Notes to fill in the flow chart from

Fridaybull Journalsmdashin classmdash5 minutes before

the bellmdashyou must write the entire timehellip

Time to Practice 1 NiCl22 K3PO4

3 S2Cl24 H2CO3

5 Cu(NO3)2

6 Sodium hypochlorite7 Silver bromide8 Hydrochloric acid9 Strontium permanganate10 Sulfur trioxide

Time to Practice 1 Nickel (II) chloride or nickelous chloride or 23 chloride

2 Potassium phosphate3 Disulfur dichlorine4 Hydrocarbonic acid

5 Copper (II) nitrate or Cupric nitrate6 NaClO7 AgBr8 HCl

9 Sr(MnO4)2

10 SO3

Time to Recall 1 What is the date of Mole Day2 What time does it begin End3 Write down the food you will be bringing in on Mole

Day4 If you had a mole of bananas how many bananas

would you have5 What is this called (Name of dude)

Mole-Particle ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use Avogadrorsquos

of 1 mole = 6022 X 1023

particles

Mole-Particle Conversions bull Chemists use Avogadrorsquos number to calculate the

number of particles in a sample of matterbull Suppose you are told that balloon contains 200 mol of

the gas argonndashand nothing elsebull You want to know how many particles are in the

balloonbull You want to change the measurement units from moles

to particlesbull Moles Ar particles Ar

Mole-Particle Conversions bull Your conversion factor is 1 mol Ar = 6022 x 1023

particles Arbull Write the given number and unit Include the chemical

symbol or formula of the substancebull Set up a factor label gridbull Use the conversion factor in the gridmdashmaking sure to

align units so that they will cancelbull Give the answer with the correct unit and the correct

number of significant digits

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Goals for Learning

bull To convert between moles and number of particlesbull To convert between mass and molesbull To convert between moles and gas volume at STPbull To use molarity in conversions involving solutionsbull To calculate the percent composition of a compoundbull To find an empirical formula from percent compositionbull To use an empirical formula to find a molecular formula

Organization of UnitVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Objectives

bull Explain what a mole isbull Convert between moles and number of particlesbull Define molar massbull Find the molar mass of an element using the

periodic tablebull Calculate the molar mass of a compoundbull Use molar mass to convert between mass and

moles

Key Terms

bull Mole (mol)bull Avogadrorsquos numberbull Atomic massbull Molar mass

Measuring Matter

bull All matter is made of different kinds of particlesbull These particles can be molecules atoms or ionsbull Elements such as helium and iron exist as single

atomsbull Other elements like H O and N are diatomic

moleculesbull Molecular compounds like CO2 and water also exist

as molecules

Measuring Matter

bull Ionic compounds like ammonium carbonate consist of cations and anions in formula units

bull Depending on the substance different names for the particles are used

bull In this unit all atoms molecules and formula units are referred to as particles

The Mole bull The particles in matter are very very smallmdashtoo small to

see even with a microscopebull Counting the number of particles in a sample is not

possible bull Instead of counting them chemists measure the number

of particles with a unit called the molebull The abbreviation for mole is mol (I suppose there is a

logical reason for this)bull The mole is a unit for measuring the amount of substance

The Mole bull The word mole means a number similar to the

word dozenbull 1 dozen eggs = 12 eggsbull 1 mole eggs = 6022 x 1023 eggsbull One mole of any substance contains 6022 x 1023

particlesbull These particles can be atoms molecules or

formula units

The Mole bull The number 6022 x 1023 is called Avogadrorsquos numberbull It is a very very large numberbull A mole of eggs is more eggs than have ever been eaten

in the history of the worldbull If you stacked a 6022 x 1023 sheets of paper the pile

would reach to the sun and back more than a million times

bull However a mole of molecules atoms and formula units is not very big

TodayhellipTodayhellip

bull Get ready for practicehellipbull Notes to fill in the flow chart from

Fridaybull Journalsmdashin classmdash5 minutes before

the bellmdashyou must write the entire timehellip

Time to Practice 1 NiCl22 K3PO4

3 S2Cl24 H2CO3

5 Cu(NO3)2

6 Sodium hypochlorite7 Silver bromide8 Hydrochloric acid9 Strontium permanganate10 Sulfur trioxide

Time to Practice 1 Nickel (II) chloride or nickelous chloride or 23 chloride

2 Potassium phosphate3 Disulfur dichlorine4 Hydrocarbonic acid

5 Copper (II) nitrate or Cupric nitrate6 NaClO7 AgBr8 HCl

9 Sr(MnO4)2

10 SO3

Time to Recall 1 What is the date of Mole Day2 What time does it begin End3 Write down the food you will be bringing in on Mole

Day4 If you had a mole of bananas how many bananas

would you have5 What is this called (Name of dude)

Mole-Particle ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use Avogadrorsquos

of 1 mole = 6022 X 1023

particles

Mole-Particle Conversions bull Chemists use Avogadrorsquos number to calculate the

number of particles in a sample of matterbull Suppose you are told that balloon contains 200 mol of

the gas argonndashand nothing elsebull You want to know how many particles are in the

balloonbull You want to change the measurement units from moles

to particlesbull Moles Ar particles Ar

Mole-Particle Conversions bull Your conversion factor is 1 mol Ar = 6022 x 1023

particles Arbull Write the given number and unit Include the chemical

symbol or formula of the substancebull Set up a factor label gridbull Use the conversion factor in the gridmdashmaking sure to

align units so that they will cancelbull Give the answer with the correct unit and the correct

number of significant digits

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Organization of UnitVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Objectives

bull Explain what a mole isbull Convert between moles and number of particlesbull Define molar massbull Find the molar mass of an element using the

periodic tablebull Calculate the molar mass of a compoundbull Use molar mass to convert between mass and

moles

Key Terms

bull Mole (mol)bull Avogadrorsquos numberbull Atomic massbull Molar mass

Measuring Matter

bull All matter is made of different kinds of particlesbull These particles can be molecules atoms or ionsbull Elements such as helium and iron exist as single

atomsbull Other elements like H O and N are diatomic

moleculesbull Molecular compounds like CO2 and water also exist

as molecules

Measuring Matter

bull Ionic compounds like ammonium carbonate consist of cations and anions in formula units

bull Depending on the substance different names for the particles are used

bull In this unit all atoms molecules and formula units are referred to as particles

The Mole bull The particles in matter are very very smallmdashtoo small to

see even with a microscopebull Counting the number of particles in a sample is not

possible bull Instead of counting them chemists measure the number

of particles with a unit called the molebull The abbreviation for mole is mol (I suppose there is a

logical reason for this)bull The mole is a unit for measuring the amount of substance

The Mole bull The word mole means a number similar to the

word dozenbull 1 dozen eggs = 12 eggsbull 1 mole eggs = 6022 x 1023 eggsbull One mole of any substance contains 6022 x 1023

particlesbull These particles can be atoms molecules or

formula units

The Mole bull The number 6022 x 1023 is called Avogadrorsquos numberbull It is a very very large numberbull A mole of eggs is more eggs than have ever been eaten

in the history of the worldbull If you stacked a 6022 x 1023 sheets of paper the pile

would reach to the sun and back more than a million times

bull However a mole of molecules atoms and formula units is not very big

TodayhellipTodayhellip

bull Get ready for practicehellipbull Notes to fill in the flow chart from

Fridaybull Journalsmdashin classmdash5 minutes before

the bellmdashyou must write the entire timehellip

Time to Practice 1 NiCl22 K3PO4

3 S2Cl24 H2CO3

5 Cu(NO3)2

6 Sodium hypochlorite7 Silver bromide8 Hydrochloric acid9 Strontium permanganate10 Sulfur trioxide

Time to Practice 1 Nickel (II) chloride or nickelous chloride or 23 chloride

2 Potassium phosphate3 Disulfur dichlorine4 Hydrocarbonic acid

5 Copper (II) nitrate or Cupric nitrate6 NaClO7 AgBr8 HCl

9 Sr(MnO4)2

10 SO3

Time to Recall 1 What is the date of Mole Day2 What time does it begin End3 Write down the food you will be bringing in on Mole

Day4 If you had a mole of bananas how many bananas

would you have5 What is this called (Name of dude)

Mole-Particle ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use Avogadrorsquos

of 1 mole = 6022 X 1023

particles

Mole-Particle Conversions bull Chemists use Avogadrorsquos number to calculate the

number of particles in a sample of matterbull Suppose you are told that balloon contains 200 mol of

the gas argonndashand nothing elsebull You want to know how many particles are in the

balloonbull You want to change the measurement units from moles

to particlesbull Moles Ar particles Ar

Mole-Particle Conversions bull Your conversion factor is 1 mol Ar = 6022 x 1023

particles Arbull Write the given number and unit Include the chemical

symbol or formula of the substancebull Set up a factor label gridbull Use the conversion factor in the gridmdashmaking sure to

align units so that they will cancelbull Give the answer with the correct unit and the correct

number of significant digits

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Objectives

bull Explain what a mole isbull Convert between moles and number of particlesbull Define molar massbull Find the molar mass of an element using the

periodic tablebull Calculate the molar mass of a compoundbull Use molar mass to convert between mass and

moles

Key Terms

bull Mole (mol)bull Avogadrorsquos numberbull Atomic massbull Molar mass

Measuring Matter

bull All matter is made of different kinds of particlesbull These particles can be molecules atoms or ionsbull Elements such as helium and iron exist as single

atomsbull Other elements like H O and N are diatomic

moleculesbull Molecular compounds like CO2 and water also exist

as molecules

Measuring Matter

bull Ionic compounds like ammonium carbonate consist of cations and anions in formula units

bull Depending on the substance different names for the particles are used

bull In this unit all atoms molecules and formula units are referred to as particles

The Mole bull The particles in matter are very very smallmdashtoo small to

see even with a microscopebull Counting the number of particles in a sample is not

possible bull Instead of counting them chemists measure the number

of particles with a unit called the molebull The abbreviation for mole is mol (I suppose there is a

logical reason for this)bull The mole is a unit for measuring the amount of substance

The Mole bull The word mole means a number similar to the

word dozenbull 1 dozen eggs = 12 eggsbull 1 mole eggs = 6022 x 1023 eggsbull One mole of any substance contains 6022 x 1023

particlesbull These particles can be atoms molecules or

formula units

The Mole bull The number 6022 x 1023 is called Avogadrorsquos numberbull It is a very very large numberbull A mole of eggs is more eggs than have ever been eaten

in the history of the worldbull If you stacked a 6022 x 1023 sheets of paper the pile

would reach to the sun and back more than a million times

bull However a mole of molecules atoms and formula units is not very big

TodayhellipTodayhellip

bull Get ready for practicehellipbull Notes to fill in the flow chart from

Fridaybull Journalsmdashin classmdash5 minutes before

the bellmdashyou must write the entire timehellip

Time to Practice 1 NiCl22 K3PO4

3 S2Cl24 H2CO3

5 Cu(NO3)2

6 Sodium hypochlorite7 Silver bromide8 Hydrochloric acid9 Strontium permanganate10 Sulfur trioxide

Time to Practice 1 Nickel (II) chloride or nickelous chloride or 23 chloride

2 Potassium phosphate3 Disulfur dichlorine4 Hydrocarbonic acid

5 Copper (II) nitrate or Cupric nitrate6 NaClO7 AgBr8 HCl

9 Sr(MnO4)2

10 SO3

Time to Recall 1 What is the date of Mole Day2 What time does it begin End3 Write down the food you will be bringing in on Mole

Day4 If you had a mole of bananas how many bananas

would you have5 What is this called (Name of dude)

Mole-Particle ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use Avogadrorsquos

of 1 mole = 6022 X 1023

particles

Mole-Particle Conversions bull Chemists use Avogadrorsquos number to calculate the

number of particles in a sample of matterbull Suppose you are told that balloon contains 200 mol of

the gas argonndashand nothing elsebull You want to know how many particles are in the

balloonbull You want to change the measurement units from moles

to particlesbull Moles Ar particles Ar

Mole-Particle Conversions bull Your conversion factor is 1 mol Ar = 6022 x 1023

particles Arbull Write the given number and unit Include the chemical

symbol or formula of the substancebull Set up a factor label gridbull Use the conversion factor in the gridmdashmaking sure to

align units so that they will cancelbull Give the answer with the correct unit and the correct

number of significant digits

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Key Terms

bull Mole (mol)bull Avogadrorsquos numberbull Atomic massbull Molar mass

Measuring Matter

bull All matter is made of different kinds of particlesbull These particles can be molecules atoms or ionsbull Elements such as helium and iron exist as single

atomsbull Other elements like H O and N are diatomic

moleculesbull Molecular compounds like CO2 and water also exist

as molecules

Measuring Matter

bull Ionic compounds like ammonium carbonate consist of cations and anions in formula units

bull Depending on the substance different names for the particles are used

bull In this unit all atoms molecules and formula units are referred to as particles

The Mole bull The particles in matter are very very smallmdashtoo small to

see even with a microscopebull Counting the number of particles in a sample is not

possible bull Instead of counting them chemists measure the number

of particles with a unit called the molebull The abbreviation for mole is mol (I suppose there is a

logical reason for this)bull The mole is a unit for measuring the amount of substance

The Mole bull The word mole means a number similar to the

word dozenbull 1 dozen eggs = 12 eggsbull 1 mole eggs = 6022 x 1023 eggsbull One mole of any substance contains 6022 x 1023

particlesbull These particles can be atoms molecules or

formula units

The Mole bull The number 6022 x 1023 is called Avogadrorsquos numberbull It is a very very large numberbull A mole of eggs is more eggs than have ever been eaten

in the history of the worldbull If you stacked a 6022 x 1023 sheets of paper the pile

would reach to the sun and back more than a million times

bull However a mole of molecules atoms and formula units is not very big

TodayhellipTodayhellip

bull Get ready for practicehellipbull Notes to fill in the flow chart from

Fridaybull Journalsmdashin classmdash5 minutes before

the bellmdashyou must write the entire timehellip

Time to Practice 1 NiCl22 K3PO4

3 S2Cl24 H2CO3

5 Cu(NO3)2

6 Sodium hypochlorite7 Silver bromide8 Hydrochloric acid9 Strontium permanganate10 Sulfur trioxide

Time to Practice 1 Nickel (II) chloride or nickelous chloride or 23 chloride

2 Potassium phosphate3 Disulfur dichlorine4 Hydrocarbonic acid

5 Copper (II) nitrate or Cupric nitrate6 NaClO7 AgBr8 HCl

9 Sr(MnO4)2

10 SO3

Time to Recall 1 What is the date of Mole Day2 What time does it begin End3 Write down the food you will be bringing in on Mole

Day4 If you had a mole of bananas how many bananas

would you have5 What is this called (Name of dude)

Mole-Particle ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use Avogadrorsquos

of 1 mole = 6022 X 1023

particles

Mole-Particle Conversions bull Chemists use Avogadrorsquos number to calculate the

number of particles in a sample of matterbull Suppose you are told that balloon contains 200 mol of

the gas argonndashand nothing elsebull You want to know how many particles are in the

balloonbull You want to change the measurement units from moles

to particlesbull Moles Ar particles Ar

Mole-Particle Conversions bull Your conversion factor is 1 mol Ar = 6022 x 1023

particles Arbull Write the given number and unit Include the chemical

symbol or formula of the substancebull Set up a factor label gridbull Use the conversion factor in the gridmdashmaking sure to

align units so that they will cancelbull Give the answer with the correct unit and the correct

number of significant digits

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Measuring Matter

bull All matter is made of different kinds of particlesbull These particles can be molecules atoms or ionsbull Elements such as helium and iron exist as single

atomsbull Other elements like H O and N are diatomic

moleculesbull Molecular compounds like CO2 and water also exist

as molecules

Measuring Matter

bull Ionic compounds like ammonium carbonate consist of cations and anions in formula units

bull Depending on the substance different names for the particles are used

bull In this unit all atoms molecules and formula units are referred to as particles

The Mole bull The particles in matter are very very smallmdashtoo small to

see even with a microscopebull Counting the number of particles in a sample is not

possible bull Instead of counting them chemists measure the number

of particles with a unit called the molebull The abbreviation for mole is mol (I suppose there is a

logical reason for this)bull The mole is a unit for measuring the amount of substance

The Mole bull The word mole means a number similar to the

word dozenbull 1 dozen eggs = 12 eggsbull 1 mole eggs = 6022 x 1023 eggsbull One mole of any substance contains 6022 x 1023

particlesbull These particles can be atoms molecules or

formula units

The Mole bull The number 6022 x 1023 is called Avogadrorsquos numberbull It is a very very large numberbull A mole of eggs is more eggs than have ever been eaten

in the history of the worldbull If you stacked a 6022 x 1023 sheets of paper the pile

would reach to the sun and back more than a million times

bull However a mole of molecules atoms and formula units is not very big

TodayhellipTodayhellip

bull Get ready for practicehellipbull Notes to fill in the flow chart from

Fridaybull Journalsmdashin classmdash5 minutes before

the bellmdashyou must write the entire timehellip

Time to Practice 1 NiCl22 K3PO4

3 S2Cl24 H2CO3

5 Cu(NO3)2

6 Sodium hypochlorite7 Silver bromide8 Hydrochloric acid9 Strontium permanganate10 Sulfur trioxide

Time to Practice 1 Nickel (II) chloride or nickelous chloride or 23 chloride

2 Potassium phosphate3 Disulfur dichlorine4 Hydrocarbonic acid

5 Copper (II) nitrate or Cupric nitrate6 NaClO7 AgBr8 HCl

9 Sr(MnO4)2

10 SO3

Time to Recall 1 What is the date of Mole Day2 What time does it begin End3 Write down the food you will be bringing in on Mole

Day4 If you had a mole of bananas how many bananas

would you have5 What is this called (Name of dude)

Mole-Particle ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use Avogadrorsquos

of 1 mole = 6022 X 1023

particles

Mole-Particle Conversions bull Chemists use Avogadrorsquos number to calculate the

number of particles in a sample of matterbull Suppose you are told that balloon contains 200 mol of

the gas argonndashand nothing elsebull You want to know how many particles are in the

balloonbull You want to change the measurement units from moles

to particlesbull Moles Ar particles Ar

Mole-Particle Conversions bull Your conversion factor is 1 mol Ar = 6022 x 1023

particles Arbull Write the given number and unit Include the chemical

symbol or formula of the substancebull Set up a factor label gridbull Use the conversion factor in the gridmdashmaking sure to

align units so that they will cancelbull Give the answer with the correct unit and the correct

number of significant digits

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Measuring Matter

bull Ionic compounds like ammonium carbonate consist of cations and anions in formula units

bull Depending on the substance different names for the particles are used

bull In this unit all atoms molecules and formula units are referred to as particles

The Mole bull The particles in matter are very very smallmdashtoo small to

see even with a microscopebull Counting the number of particles in a sample is not

possible bull Instead of counting them chemists measure the number

of particles with a unit called the molebull The abbreviation for mole is mol (I suppose there is a

logical reason for this)bull The mole is a unit for measuring the amount of substance

The Mole bull The word mole means a number similar to the

word dozenbull 1 dozen eggs = 12 eggsbull 1 mole eggs = 6022 x 1023 eggsbull One mole of any substance contains 6022 x 1023

particlesbull These particles can be atoms molecules or

formula units

The Mole bull The number 6022 x 1023 is called Avogadrorsquos numberbull It is a very very large numberbull A mole of eggs is more eggs than have ever been eaten

in the history of the worldbull If you stacked a 6022 x 1023 sheets of paper the pile

would reach to the sun and back more than a million times

bull However a mole of molecules atoms and formula units is not very big

TodayhellipTodayhellip

bull Get ready for practicehellipbull Notes to fill in the flow chart from

Fridaybull Journalsmdashin classmdash5 minutes before

the bellmdashyou must write the entire timehellip

Time to Practice 1 NiCl22 K3PO4

3 S2Cl24 H2CO3

5 Cu(NO3)2

6 Sodium hypochlorite7 Silver bromide8 Hydrochloric acid9 Strontium permanganate10 Sulfur trioxide

Time to Practice 1 Nickel (II) chloride or nickelous chloride or 23 chloride

2 Potassium phosphate3 Disulfur dichlorine4 Hydrocarbonic acid

5 Copper (II) nitrate or Cupric nitrate6 NaClO7 AgBr8 HCl

9 Sr(MnO4)2

10 SO3

Time to Recall 1 What is the date of Mole Day2 What time does it begin End3 Write down the food you will be bringing in on Mole

Day4 If you had a mole of bananas how many bananas

would you have5 What is this called (Name of dude)

Mole-Particle ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use Avogadrorsquos

of 1 mole = 6022 X 1023

particles

Mole-Particle Conversions bull Chemists use Avogadrorsquos number to calculate the

number of particles in a sample of matterbull Suppose you are told that balloon contains 200 mol of

the gas argonndashand nothing elsebull You want to know how many particles are in the

balloonbull You want to change the measurement units from moles

to particlesbull Moles Ar particles Ar

Mole-Particle Conversions bull Your conversion factor is 1 mol Ar = 6022 x 1023

particles Arbull Write the given number and unit Include the chemical

symbol or formula of the substancebull Set up a factor label gridbull Use the conversion factor in the gridmdashmaking sure to

align units so that they will cancelbull Give the answer with the correct unit and the correct

number of significant digits

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

The Mole bull The particles in matter are very very smallmdashtoo small to

see even with a microscopebull Counting the number of particles in a sample is not

possible bull Instead of counting them chemists measure the number

of particles with a unit called the molebull The abbreviation for mole is mol (I suppose there is a

logical reason for this)bull The mole is a unit for measuring the amount of substance

The Mole bull The word mole means a number similar to the

word dozenbull 1 dozen eggs = 12 eggsbull 1 mole eggs = 6022 x 1023 eggsbull One mole of any substance contains 6022 x 1023

particlesbull These particles can be atoms molecules or

formula units

The Mole bull The number 6022 x 1023 is called Avogadrorsquos numberbull It is a very very large numberbull A mole of eggs is more eggs than have ever been eaten

in the history of the worldbull If you stacked a 6022 x 1023 sheets of paper the pile

would reach to the sun and back more than a million times

bull However a mole of molecules atoms and formula units is not very big

TodayhellipTodayhellip

bull Get ready for practicehellipbull Notes to fill in the flow chart from

Fridaybull Journalsmdashin classmdash5 minutes before

the bellmdashyou must write the entire timehellip

Time to Practice 1 NiCl22 K3PO4

3 S2Cl24 H2CO3

5 Cu(NO3)2

6 Sodium hypochlorite7 Silver bromide8 Hydrochloric acid9 Strontium permanganate10 Sulfur trioxide

Time to Practice 1 Nickel (II) chloride or nickelous chloride or 23 chloride

2 Potassium phosphate3 Disulfur dichlorine4 Hydrocarbonic acid

5 Copper (II) nitrate or Cupric nitrate6 NaClO7 AgBr8 HCl

9 Sr(MnO4)2

10 SO3

Time to Recall 1 What is the date of Mole Day2 What time does it begin End3 Write down the food you will be bringing in on Mole

Day4 If you had a mole of bananas how many bananas

would you have5 What is this called (Name of dude)

Mole-Particle ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use Avogadrorsquos

of 1 mole = 6022 X 1023

particles

Mole-Particle Conversions bull Chemists use Avogadrorsquos number to calculate the

number of particles in a sample of matterbull Suppose you are told that balloon contains 200 mol of

the gas argonndashand nothing elsebull You want to know how many particles are in the

balloonbull You want to change the measurement units from moles

to particlesbull Moles Ar particles Ar

Mole-Particle Conversions bull Your conversion factor is 1 mol Ar = 6022 x 1023

particles Arbull Write the given number and unit Include the chemical

symbol or formula of the substancebull Set up a factor label gridbull Use the conversion factor in the gridmdashmaking sure to

align units so that they will cancelbull Give the answer with the correct unit and the correct

number of significant digits

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

The Mole bull The word mole means a number similar to the

word dozenbull 1 dozen eggs = 12 eggsbull 1 mole eggs = 6022 x 1023 eggsbull One mole of any substance contains 6022 x 1023

particlesbull These particles can be atoms molecules or

formula units

The Mole bull The number 6022 x 1023 is called Avogadrorsquos numberbull It is a very very large numberbull A mole of eggs is more eggs than have ever been eaten

in the history of the worldbull If you stacked a 6022 x 1023 sheets of paper the pile

would reach to the sun and back more than a million times

bull However a mole of molecules atoms and formula units is not very big

TodayhellipTodayhellip

bull Get ready for practicehellipbull Notes to fill in the flow chart from

Fridaybull Journalsmdashin classmdash5 minutes before

the bellmdashyou must write the entire timehellip

Time to Practice 1 NiCl22 K3PO4

3 S2Cl24 H2CO3

5 Cu(NO3)2

6 Sodium hypochlorite7 Silver bromide8 Hydrochloric acid9 Strontium permanganate10 Sulfur trioxide

Time to Practice 1 Nickel (II) chloride or nickelous chloride or 23 chloride

2 Potassium phosphate3 Disulfur dichlorine4 Hydrocarbonic acid

5 Copper (II) nitrate or Cupric nitrate6 NaClO7 AgBr8 HCl

9 Sr(MnO4)2

10 SO3

Time to Recall 1 What is the date of Mole Day2 What time does it begin End3 Write down the food you will be bringing in on Mole

Day4 If you had a mole of bananas how many bananas

would you have5 What is this called (Name of dude)

Mole-Particle ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use Avogadrorsquos

of 1 mole = 6022 X 1023

particles

Mole-Particle Conversions bull Chemists use Avogadrorsquos number to calculate the

number of particles in a sample of matterbull Suppose you are told that balloon contains 200 mol of

the gas argonndashand nothing elsebull You want to know how many particles are in the

balloonbull You want to change the measurement units from moles

to particlesbull Moles Ar particles Ar

Mole-Particle Conversions bull Your conversion factor is 1 mol Ar = 6022 x 1023

particles Arbull Write the given number and unit Include the chemical

symbol or formula of the substancebull Set up a factor label gridbull Use the conversion factor in the gridmdashmaking sure to

align units so that they will cancelbull Give the answer with the correct unit and the correct

number of significant digits

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

The Mole bull The number 6022 x 1023 is called Avogadrorsquos numberbull It is a very very large numberbull A mole of eggs is more eggs than have ever been eaten

in the history of the worldbull If you stacked a 6022 x 1023 sheets of paper the pile

would reach to the sun and back more than a million times

bull However a mole of molecules atoms and formula units is not very big

TodayhellipTodayhellip

bull Get ready for practicehellipbull Notes to fill in the flow chart from

Fridaybull Journalsmdashin classmdash5 minutes before

the bellmdashyou must write the entire timehellip

Time to Practice 1 NiCl22 K3PO4

3 S2Cl24 H2CO3

5 Cu(NO3)2

6 Sodium hypochlorite7 Silver bromide8 Hydrochloric acid9 Strontium permanganate10 Sulfur trioxide

Time to Practice 1 Nickel (II) chloride or nickelous chloride or 23 chloride

2 Potassium phosphate3 Disulfur dichlorine4 Hydrocarbonic acid

5 Copper (II) nitrate or Cupric nitrate6 NaClO7 AgBr8 HCl

9 Sr(MnO4)2

10 SO3

Time to Recall 1 What is the date of Mole Day2 What time does it begin End3 Write down the food you will be bringing in on Mole

Day4 If you had a mole of bananas how many bananas

would you have5 What is this called (Name of dude)

Mole-Particle ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use Avogadrorsquos

of 1 mole = 6022 X 1023

particles

Mole-Particle Conversions bull Chemists use Avogadrorsquos number to calculate the

number of particles in a sample of matterbull Suppose you are told that balloon contains 200 mol of

the gas argonndashand nothing elsebull You want to know how many particles are in the

balloonbull You want to change the measurement units from moles

to particlesbull Moles Ar particles Ar

Mole-Particle Conversions bull Your conversion factor is 1 mol Ar = 6022 x 1023

particles Arbull Write the given number and unit Include the chemical

symbol or formula of the substancebull Set up a factor label gridbull Use the conversion factor in the gridmdashmaking sure to

align units so that they will cancelbull Give the answer with the correct unit and the correct

number of significant digits

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

TodayhellipTodayhellip

bull Get ready for practicehellipbull Notes to fill in the flow chart from

Fridaybull Journalsmdashin classmdash5 minutes before

the bellmdashyou must write the entire timehellip

Time to Practice 1 NiCl22 K3PO4

3 S2Cl24 H2CO3

5 Cu(NO3)2

6 Sodium hypochlorite7 Silver bromide8 Hydrochloric acid9 Strontium permanganate10 Sulfur trioxide

Time to Practice 1 Nickel (II) chloride or nickelous chloride or 23 chloride

2 Potassium phosphate3 Disulfur dichlorine4 Hydrocarbonic acid

5 Copper (II) nitrate or Cupric nitrate6 NaClO7 AgBr8 HCl

9 Sr(MnO4)2

10 SO3

Time to Recall 1 What is the date of Mole Day2 What time does it begin End3 Write down the food you will be bringing in on Mole

Day4 If you had a mole of bananas how many bananas

would you have5 What is this called (Name of dude)

Mole-Particle ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use Avogadrorsquos

of 1 mole = 6022 X 1023

particles

Mole-Particle Conversions bull Chemists use Avogadrorsquos number to calculate the

number of particles in a sample of matterbull Suppose you are told that balloon contains 200 mol of

the gas argonndashand nothing elsebull You want to know how many particles are in the

balloonbull You want to change the measurement units from moles

to particlesbull Moles Ar particles Ar

Mole-Particle Conversions bull Your conversion factor is 1 mol Ar = 6022 x 1023

particles Arbull Write the given number and unit Include the chemical

symbol or formula of the substancebull Set up a factor label gridbull Use the conversion factor in the gridmdashmaking sure to

align units so that they will cancelbull Give the answer with the correct unit and the correct

number of significant digits

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Time to Practice 1 NiCl22 K3PO4

3 S2Cl24 H2CO3

5 Cu(NO3)2

6 Sodium hypochlorite7 Silver bromide8 Hydrochloric acid9 Strontium permanganate10 Sulfur trioxide

Time to Practice 1 Nickel (II) chloride or nickelous chloride or 23 chloride

2 Potassium phosphate3 Disulfur dichlorine4 Hydrocarbonic acid

5 Copper (II) nitrate or Cupric nitrate6 NaClO7 AgBr8 HCl

9 Sr(MnO4)2

10 SO3

Time to Recall 1 What is the date of Mole Day2 What time does it begin End3 Write down the food you will be bringing in on Mole

Day4 If you had a mole of bananas how many bananas

would you have5 What is this called (Name of dude)

Mole-Particle ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use Avogadrorsquos

of 1 mole = 6022 X 1023

particles

Mole-Particle Conversions bull Chemists use Avogadrorsquos number to calculate the

number of particles in a sample of matterbull Suppose you are told that balloon contains 200 mol of

the gas argonndashand nothing elsebull You want to know how many particles are in the

balloonbull You want to change the measurement units from moles

to particlesbull Moles Ar particles Ar

Mole-Particle Conversions bull Your conversion factor is 1 mol Ar = 6022 x 1023

particles Arbull Write the given number and unit Include the chemical

symbol or formula of the substancebull Set up a factor label gridbull Use the conversion factor in the gridmdashmaking sure to

align units so that they will cancelbull Give the answer with the correct unit and the correct

number of significant digits

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Time to Practice 1 Nickel (II) chloride or nickelous chloride or 23 chloride

2 Potassium phosphate3 Disulfur dichlorine4 Hydrocarbonic acid

5 Copper (II) nitrate or Cupric nitrate6 NaClO7 AgBr8 HCl

9 Sr(MnO4)2

10 SO3

Time to Recall 1 What is the date of Mole Day2 What time does it begin End3 Write down the food you will be bringing in on Mole

Day4 If you had a mole of bananas how many bananas

would you have5 What is this called (Name of dude)

Mole-Particle ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use Avogadrorsquos

of 1 mole = 6022 X 1023

particles

Mole-Particle Conversions bull Chemists use Avogadrorsquos number to calculate the

number of particles in a sample of matterbull Suppose you are told that balloon contains 200 mol of

the gas argonndashand nothing elsebull You want to know how many particles are in the

balloonbull You want to change the measurement units from moles

to particlesbull Moles Ar particles Ar

Mole-Particle Conversions bull Your conversion factor is 1 mol Ar = 6022 x 1023

particles Arbull Write the given number and unit Include the chemical

symbol or formula of the substancebull Set up a factor label gridbull Use the conversion factor in the gridmdashmaking sure to

align units so that they will cancelbull Give the answer with the correct unit and the correct

number of significant digits

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Time to Recall 1 What is the date of Mole Day2 What time does it begin End3 Write down the food you will be bringing in on Mole

Day4 If you had a mole of bananas how many bananas

would you have5 What is this called (Name of dude)

Mole-Particle ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use Avogadrorsquos

of 1 mole = 6022 X 1023

particles

Mole-Particle Conversions bull Chemists use Avogadrorsquos number to calculate the

number of particles in a sample of matterbull Suppose you are told that balloon contains 200 mol of

the gas argonndashand nothing elsebull You want to know how many particles are in the

balloonbull You want to change the measurement units from moles

to particlesbull Moles Ar particles Ar

Mole-Particle Conversions bull Your conversion factor is 1 mol Ar = 6022 x 1023

particles Arbull Write the given number and unit Include the chemical

symbol or formula of the substancebull Set up a factor label gridbull Use the conversion factor in the gridmdashmaking sure to

align units so that they will cancelbull Give the answer with the correct unit and the correct

number of significant digits

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Mole-Particle ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use Avogadrorsquos

of 1 mole = 6022 X 1023

particles

Mole-Particle Conversions bull Chemists use Avogadrorsquos number to calculate the

number of particles in a sample of matterbull Suppose you are told that balloon contains 200 mol of

the gas argonndashand nothing elsebull You want to know how many particles are in the

balloonbull You want to change the measurement units from moles

to particlesbull Moles Ar particles Ar

Mole-Particle Conversions bull Your conversion factor is 1 mol Ar = 6022 x 1023

particles Arbull Write the given number and unit Include the chemical

symbol or formula of the substancebull Set up a factor label gridbull Use the conversion factor in the gridmdashmaking sure to

align units so that they will cancelbull Give the answer with the correct unit and the correct

number of significant digits

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Mole-Particle Conversions bull Chemists use Avogadrorsquos number to calculate the

number of particles in a sample of matterbull Suppose you are told that balloon contains 200 mol of

the gas argonndashand nothing elsebull You want to know how many particles are in the

balloonbull You want to change the measurement units from moles

to particlesbull Moles Ar particles Ar

Mole-Particle Conversions bull Your conversion factor is 1 mol Ar = 6022 x 1023

particles Arbull Write the given number and unit Include the chemical

symbol or formula of the substancebull Set up a factor label gridbull Use the conversion factor in the gridmdashmaking sure to

align units so that they will cancelbull Give the answer with the correct unit and the correct

number of significant digits

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Mole-Particle Conversions bull Your conversion factor is 1 mol Ar = 6022 x 1023

particles Arbull Write the given number and unit Include the chemical

symbol or formula of the substancebull Set up a factor label gridbull Use the conversion factor in the gridmdashmaking sure to

align units so that they will cancelbull Give the answer with the correct unit and the correct

number of significant digits

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Mole-Particle Conversions bull You tryhellipbull How many moles are in 435 x 1024 molecules of

CO2bull How many formula units are in 315 mol of sodium

oxide

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Molar Mass bull We know that 1 mole of a substance is a certain

number of particlesmdashregardless of what the particles are

bull 1 mole of donuts is 6022 x 1023 donutsbull 1 mole of desks is 6022 x 1023 desksbull 1 mole of yen is 6022 x 1023 yen

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Molar Mass bull 1 mole of a substance also has a certain massmdashbut

it is different for every substancebull 1 mole of donuts does not have the same mass as 1

mole of desks but they still contain the same number of each

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Molar Mass bull It is impossible to count the particles in a sample of matter

but it is easy to find the samplersquos massbull If you know the mass of a substance you can determine the

number of moles in itbull To make a mass-to-mole conversion you need to know

about another piece of information from the periodic tablebull Atomic numbermdashnumber of protons and electrons in an atombull Atomic mass or molar mass is the mass of one atom of the

substance or the mass of one mole of the substance

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Molar Mass bull If you want to know the atomic mass (mass of one atom) the

number has units of amu (atomic mass units)bull If you want to know the molar mass (mass of one mole of

atoms) the number has units of gmol (grams of substance per mole of substance)

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

The Molar Mass of Elementsbull The molar mass of carbon is 12 gmolbull The molar mass of oxygen is 16 gmolbull This means that 6022 x 1023 atoms of carbon (1 mol) has a

mass of 12gbull This also means that 6022 x 1023 atoms of oxygen (1 mol)

has a mass of 16g

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Review Mini

bull What is a dozenbull What is a molebull How many atoms of H are in a dozen of Hbull How many atoms of H are in a mole of Hbull What is the mass of one H atombull What is the mass of 1 mole of H atomsbull What is the mass of 1 O atombull What is the mass of 1 mole of O atomsbull What is the mass of 1 mole of H2O

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

TodayhellipTodayhellip

bull Short review timehellipbull Get boardsbull Notesmdashmolar mass mass to mole

conversions gas volume to mole conversions solution volume to mole conversions percent composition and empirical formula concepthellip

bull HWmdashreview 1 and 2 due tomorrow

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Review timehellipReview timehellip

1 CaI22 NaNO3

3 FeCl34 SO2

5 CoF2∙3H2O6 Lithium nitride7 Aluminum hydroxide8 Carbon tetrabromide9 Cupric nitrite10Magnesium acetate dihydrate

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Review timehellipReview timehellip

11What number represents a mole12How many moles of He is 635 x

1026 particles of He13When you see that magnesium has

a mass number of 2431 what are the units we will be dealing with

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

AnswersAnswers

1 Calcium iodide2 Sodium nitrate3 Iron (III) chloride or ferric chloride4 Sulfur dioxide5 Cobalt (II) fluoride trihydrate6 Li3N7 Al(OH)3

8 CBr4

9 Cu(NO2)2

10Mg(C2H3O2)2∙2H2O

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

AnswersAnswers

116022 x 1023 121050 moles13grams mole

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

The Molar Mass of Compoundsbull To find the molar mass of a compound of two or more

elements add the masses of 1 mol of each atom in the compounds formula or formula unit

bull For example to find the molar mass of CO2 count the number of C and O atoms in the formula

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

The Molar Mass of Compoundsbull Then locate the molar mass of carbon and oxygen on the

periodic tablebull Add the molar masses of each carbon an oxygen that make

up the formulabull CO2 1 C and 2 O C = 1201gmol O = 160gmol O =

160gmol = 4401 gmolbull CO2 1C(1201gmol) + 2O(160gmol) = 4401 gmol

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

The Molar Mass of Compoundsbull You tryhellipbull Calculate the molar mass of the ionic compound

Ba(C2H3O2)2bull Calculate the molar mass of ammonium sulfate

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Mole-Mass ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molar mass in gmol

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Mole-Mass Conversionsbull Molar mass can be used to convert between the mass of a

sample and the number of moles in that samplebull If you know a samplersquos mass you can find the number of

moles in the samplebull If you know how many moles are in a sample you can find its

massbull Write the given number and unit as well as the formula for the

substance

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Mole-Mass Conversionsbull Set up a factor label gridbull Set up the conversion factor of grams per mole or moles per

gram depending on your initial given informationbull Use the atomic molar mass if converting atoms or use the

molecular molar mass if converting compoundsbull Write the answer with the correct units and the correct

number of significant digits

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Mole-Mass Conversionsbull Examplebull What is the molar mass of carbon dioxidebull How many molecules are in 1 dozen carbon monoxidebull How many molecules are in 1 mole of carbon dioxidebull How many moles are in 2652g of CO2bull What is the mass in grams of 325 mol of NaBr

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Mini QuizMini Quiz1 How many grams are in 100 mole of calcium phosphate2 How many grams are in 320 moles of calcium phosphate3 How many molecules are in 412 moles of calcium phosphate4 How many molecules are in 29858g of calcium phosphate5 How many grams in 324 x 1025 molecules of calcium

phosphate6 What is the molarity of a solution that has 1536g of Ca(NO3)2 in

12L of total solution7 How many liters does 402g of O2 gas take up at STP

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Objectives

bull Define STP and standard molar volumebull Convert between gas volume moles mass and

number of particlesbull Calculate the molarity of a solutionbull Calculate the mass of solutebull Calculate the volume of a solution

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Key Terms

bull Atmospherebull Standard temperature and pressure (STP)bull Standard molar volumebull Concentratedbull Dilutebull Concentrationbull Molarity

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Molar VolumeVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use 1 mole of a gas at STP

takes up 224L of space

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Molar Volume

bull Gases have a property that liquids and solids do not have

bull Under certain conditions 1 mol of any gas has a volume of 224L

bull The two conditions that make this true arehellipbull A temperature of 0ordmCbull A pressure of 1 atmosphere (atm)

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Molar Volume

bull Atmosphere (atm) is a unit for pressurebull The air pressure at sea level is a bout 1 atmbull The two conditions previously mentioned are

standard temperature and pressure (STP)bull For now it is important to know that 1 mol of any

gas at STP has a volume of 224Lbull This value is called standard molar volume

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Molar Volume

bull For gases at STP standard molar volume 224Lmol is used to convert between gas volume and moles

bull This is a conversion factor that we can use in our factor label grid

bull IMPORTANT This conversion factor only works at STP

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Molar Volume

bull Examplebull What is the volume of 150 mol of CO2 STP

bull You tryhellipbull How many moles are in 753L of O2 at STP

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Molarity ConversionsVolume of

a solution

Number of

Moles

Volume of a

gas at STP

Number of

particlesMass

Percent composition empirical and

molecular formulas

Use molarity (M) in moles L

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

The Molarity of Solutions

bull We discussed solutions in Unit 2bull Solutions are homogenous mixturesbull They consist of one or more solutes dissolved in a

solvent

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Concentration and Molarity

bull Solutions can be concentrated or dilute depending on the amount of solute and solvent

bull A concentrated solution has more solute compared to another solution with the same volume

bull A dilute solution has less solute compared to another solution

bull Think of making a pitcher of pink lemonadebull Mmmmmmmmmmmmmmmmmmm

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Concentration and Molarity

bull The directions state for you to add 4-13 cans of cold water to the concentrate

bull If you add 3 cans of water to the concentrate then the lemonade will be very concentrated or strong

bull If you added 7 cans of water the lemonade would be very dilute or weak

bull Strong and weak concentrated or dilute are qualitative descriptions that are too vague for chemists to use so chemists use different units to describe concentration

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Concentration and Molarity

bull Chemists use units to measure concentration that make the measurement quantitative

bull The units of solution concentration is called molarity (M)

bull Molarity is moles of solute liters of entire solutionbull The more moles of solute in a given amount of

solution the more concentrated it is and the higher the molarity

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Example

bull The volume of an aqueous solution is 150L It contains 125g of NaCl What is the molarity of the solution

bull 125g NaCl is 0241 moles NaClbull 0214 moles NaCl in 150L of solution ishellipbull 0143M NaClbull Practicehellipbull The volume of a solution is 167L It contains 390g of

diatomic bromine What is the molarity of the solution

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Today amp This WeekhellipToday amp This WeekhellipIf you would like extra credit the next few lines will be extremely important

You can bring in a pumpkin and make it go ldquoBoomrdquoIt must be carved and cleaned outmdashbut leave the eyes nose amp mouth pieces in

placeThe first 2 people per class to answer my riddle get to bring one in

Here is the dealhellipI will not accept an answer todaymdashguesses should be turned in no earlier than

tomorrow during brunchMr Habs is the middle man You must give him your guess with your name

hour date time and a spooky drawingOnly one guess per student per day

Oh yeah quest is ThursdayHere is the riddlehellipWhat do you get when you cross a vampire with a snowman

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Mini QuizMini Quiz1 How many grams are in 320 moles of calcium

phosphate2 How many molecules are in 412 moles of calcium

phosphate3 How many molecules are in 29858g of calcium

phosphate4 How many grams in 324 x 1025 molecules of calcium

phosphate5 What is the molarity of a solution that has 1536g of

Ca(NO3)2 in 12L of total solution6 How many liters does 402g of O2 gas take up at STP

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

More on Molarity

bull The definition of molarity involves three factors molesL moles and liters

bull If you know any two of the three you can solve for the third

bull Examplehellipbull A 135M solution of KF has a volume of 133L How

many moles of solute does it contain How many grams

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

More on Molarity

bull Anotherhellipbull An ammonium chloride solution has a concentration of

0573M It contains 0323 mol of solute What is the volume of the solution

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Conversion Review

MolesMass of

particles

Gas volume STP

Solrsquon Volume

Use molarity in FL Grid

Use 224L molar volume at STP

Molar Mass in FL

Grid

Avogadrorsquos

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

HW ProblemHW Problem

bull How many moles of Cu are found in 155g of copper

bull The density of copper is 892 gcm3 How many atoms of copper are found in a sheet of copper that measures 8 inches by 12 inches Assume the sheet is 2mm in thickness

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Todayhellip

bull Practice quizhellipbull Notes Composition and Empirical

Formulamdashpick up from deskbull HW sheet for tonight (U have)

bull Lesson 34 + HW sheet due tomorrowbull Thursday Questmdashbig one over lots of

stuff (20 old) - (80 new)bull Pumpkin Friday + lab

bull Extra Credit WinnersmdashTomPam amp Alex

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Objectivesbull Get out your calculator periodic table sheet of paper and

flow chart for conversions (page 1 of this unit)1 Convert 220 moles of sodium nitrate to gramsmdashdo not

ask anyone for the formula for nitrate2 Convert 350 grams of silver acetate to moles of silver

acetatemdashon your own3 How many molecules of sulfur dioxide are found in 117L

of this gas at STP4 How many moles of NaCl are contained in 255mL of

055M NaCl5 How many grams

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Objectives

bull Find the total molar mass for each element in a compound

bull Find the percent composition of a compound

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Percent Composition

bull Compounds have a definite composition given by their formula and formula units

bull Water for example contains 2 atoms of H and 1 atom of O for every molecule of water

bull Each mole of water contains 2 moles of H and 2 moles of O for every mole of water

bull If we had exactly 1 mole of water there would be 202g of H and 160g of O

bull The total molar mass would be 1802g

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Percent Composition

bull This breakdown can be expressed as a percentage called percent composition

bull Percent composition tells the percentage by mass of each element in a compound

bull 2021802 for H = 112bull 1601802 for O = 888bull The two percentages add up to 100 or very close

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Percent Composition

bull Try for carbon tetrafluodridebull Try for calcium acetatebull SF6

bull NH3bull Plumbous carbonatebull Potassium nitratebull A compound has a molar mass of 424gmol It contains

elements X and Y The total molar mass of element X is 69gmol What is the percentage of this compound

bull What is the percentage of the other

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Empirical and Molecular Formulas

bull An empirical formula shows the smallest whole number ratio of atoms in a compound

bull Sometimes an empirical formula is the compoundrsquos chemical formula

bull If it is not the subscripts in the empirical formula are important clues to the chemical formula

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Types of Formulas

bull An example of an empirical formula is dextrosebull For every 1 mol of C there are 2 mol of H and 1 mol of Obull A molecule of dextrose always has 6 atoms of C 12 atoms

of H and 6 atoms of Obull C6H12O6 is the molecular formula of dextrosebull A molecular formula gives the actual number of atoms in a

moleculebull Molecular formulas is synonymous with chemical formula

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Types of Formulas

bull Both ionic and molecular formulas have empirical formulas

bull But only molecular compounds have molecular formulas

bull Ionic compounds have formula units

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Types of Formulas

bull An empirical formula shows the simplest ratio of atoms in a compound

bull A molecular formula or chemical formula shows the actual number of atoms in one molecule

bull A formula unit shows the simplest ratio of cations to anions in an ionic compound

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Determining Empirical Formulas

bull A mole ratio is a ratio or fraction that compares the moles of one substance to the moles of another substance

bull Mole ratio for water is 2 mol H 1 mol O

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Determining Empirical Formulasbull Steps1 Assume you have a 100g sample of the given compound If you

know its composition you can change each percent symbol to grams Keep the number the same for example 30 becomes 30g

bull (if you are given a mass for each element skip the first step)2 For each element convert grams to moles using molar mass (treat

all elements as monatomic and remember sig figs)3 Create a mole ratio using the mole amounts from step 2 by dividing

all mole components by the smallest number of moles4 The numbers in the simplest ratio of step 3 become the subscripts

for the chemical formula Write the empirical formula using these values

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

BOOBOO

bull We have the following to do for todayhellip

bull Finish notes (man there are a lot of notes)

bull Lab Day is pushed until Monday so that means that Quest day is

now pushed back to Weds bull After notes we can say Whoa

With a fiery pumpkin face

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Determining Empirical Formulasbull Examplebull What is the empirical formula of an unknown substance

that contains 304 nitrogen and 696 oxygen by massbull What is the empirical formula of a compound that contains

800 carbon and 200 hydrogen by massbull What is the empirical formula of a molecular compound

that contains 437g of phosphorus and 563g of oxygenbull A compound contains 420g of carbon and 421 x 1023

atoms of hydrogen and 105 mole of oxygen What is the empirical formula of this compound

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Molecular Formulas and Hydratesbull A molecular formula is either the empirical formula or a

multiple of the empirical formulabull molecular formula = n (empirical formula)bull n must be a whole numberbull For the compound dextrose n = 6bull Empirical formula = CH2Obull Molecular formula = C6H12O6 = 6 (CH2O)bull Ex credit Q for the Questhellipare dextrose and glucose the

same thing If not how can they have the same molecular formula

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Determining Molecular Formulas

bull To find the molecular formula of a compound you must know two thingshellip

bull the empirical formulabull the molar mass of the compoundbull Think of dextrose again for examplebull Suppose you do not know its molecular formula

but you know its empirical formula and that the mass of 1 mol of dextrose is 1800 gmol

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Determining Molecular Formulasbull Calculate the mass of the empirical formulamdashthis is not necessarily

the molar mass of the compoundbull For dextrosehellipbull 1201gmol + 2(101 gmol) + 160 gmol =bull 3002 gmolbull Set up the followinghellipbull Molar mass of compound = n (empirical formula mass)bull 1800 gmol = n (3002 gmol)bull n = 6bull So multiply the subscripts of the empirical formula by 6 to gethellipbull C6H12O6

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Examplesbull The empirical formula of a compound is NO2 The molar

mass of the compound is 920 gmol What is the molecular formula

bull The empirical formula of a compound is CH The molar mass of the compound is 780 gmol What is the molecular formula

bull An unknown compound contains 217g of C 0362g of H and 0966g of oxygen Its molar mass is 1160 gmol What are its empirical and molecular formulas

bull An unknown compound contains 218g of phosphorus and 282g of O Its molar mass is 284 gmol What are its empirical and molecular formulas

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Hydratesbull Some compounds have molecules of water trapped as

part of the compoundbull Hydrates are compounds that are chemically combined

with water in a specific ratiobull The compound in a hydrate is usually on ionic compoundbull In a hydratersquos empirical formula the water molecules are

written a the endbull For example Ni(NO3)2 6H2O shows that there are 6 water

molecules with each formula unit of nickel (II) nitratebull The dot in the formula is NOT a multiplication sign

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Hydrates

bull On a larger scale this tells us that there are 6 moles of water molecules for every mole of nickel (II) nitrate

bull When a hydrate is heated the water molecules leave and mix with the surrounding air

bull What remains after heating is the ionic compound without the water

bull Its formula unit shows no water moleculesbull CuSO45H2O + heat CuSO4

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Hydrates

bull Suppose you measure the mass of a sample of hydratebull Then you heat it until the water is gonebull You measure the mass of the compound that is leftbull You know the followingbull Mass of hydratebull Mass of compound without waterbull Mass of water in sample (hydrate mass ndash compound

mass)

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Hydrates

bull From this information you can find the empirical formula of the hydrate

bull It is based on the ratio of moles of the compound to moles of water

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Example

bull A hydrate of magnesium sulfate is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 565gbull Mass of compound after heating = 276g

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

Example

bull A hydrate of sodium sulfide is heated with the following results What is the empirical formula of the hydrate

bull Mass of hydrate before heating = 154gbull Mass of compound after heating = 50 g

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics

PhysicsPhysicsbull Sit down in quest seats and read the

followinghellipbull Be silent during prayer and announcementsmdashif you talk you cannot work on the quest

bull Todayrsquos Questmdashyou have the class period to finish itmdashbut you cannot ask me any

questions whatsoeverbull Calculator equation sheet (not sheets) can

be on your deskbull This is the last grade for this 1st MP

bull There will be big changes on Mondayhellip

• Chemical Quantities
• But firsthellip
• Answers
• And secondhellip
• The Daily Journal
• Ready
• Goals for Learning
• Organization of Unit
• Objectives
• Key Terms
• Measuring Matter
• Slide 12
• The Mole
• Slide 14
• Slide 15
• Todayhellip
• Time to Practice
• Slide 18
• Time to Recall
• Mole-Particle Conversions
• Mole-Particle Conversions
• Slide 22
• Slide 23
• Molar Mass
• Slide 25
• Slide 26
• Slide 27
• The Molar Mass of Elements
• Review Mini
• Slide 30
• Review timehellip
• Slide 32
• Slide 33
• Slide 34
• The Molar Mass of Compounds
• Slide 36
• Slide 37
• Mole-Mass Conversions
• Slide 39
• Slide 40
• Slide 41
• Mini Quiz
• Slide 43
• Slide 44
• Molar Volume
• Slide 46
• Slide 47
• Slide 48
• Slide 49
• Molarity Conversions
• The Molarity of Solutions
• Concentration and Molarity
• Slide 53
• Slide 54
• Example
• Today amp This Weekhellip
• Slide 57
• More on Molarity
• Slide 59
• Conversion Review
• HW Problem
• Slide 62
• Slide 63
• Slide 64
• Percent Composition
• Slide 66
• Slide 67
• Empirical and Molecular Formulas
• Types of Formulas
• Slide 70
• Slide 71
• Determining Empirical Formulas
• Slide 73
• BOO
• Slide 75
• Molecular Formulas and Hydrates
• Determining Molecular Formulas
• Slide 78
• Examples
• Hydrates
• Slide 81
• Slide 82
• Slide 83
• Example
• Slide 85
• Physics