c: 28 march 2012
DESCRIPTION
C: 28 March 2012. Grab your clicker! Take Out Your Unit 6 Packet Objective : You will be able to: define and use in context vocabulary relating to solutions and solubility model and describe the process of dissolution Do Now : Is salt water a homogeneous mixture or a heterogeneous mixture? - PowerPoint PPT PresentationTRANSCRIPT
C: 28 March 2012
Grab your clicker! Take Out Your Unit 6 Packet Objective: You will be able to:
define and use in context vocabulary relating to solutions and solubility
model and describe the process of dissolution
Do Now: Is salt water a homogeneous mixture or a heterogeneous mixture?
What classification of matter is air?
C: Agenda
I. Do nowII. Vocab notes and practiceIII. Dissolution videoIV. Dissolution activityV. Pre-lab
Homework: Unit 7 Packet p. 3: tomorrowRead p. 4-5: by tomorrow; be familiar with
procedure!Did you turn in your Unit 6 Packet?!
Pre-quizWhich of the following is a solution?
1 2 3 4
0% 0%0%0%
1. Salt water2. Sand and
water3. Oil and water4. All of the
above
Reactions in aqueous solutions
The reactions in your body (digestion, cellular respiration, etc., etc.) all happen in water!
Most reactions on earth happen in water
Essential Questions
How does the solution process occur? How does something dissolve?
What influences the solution process? What makes something dissolve, or
not dissolve or dissolve fast or slow?
Solutions Vocabulary
solution: a homogeneous mixture of a solute dissolved in a solvent
solvent: the part of a solution doing the dissolving (often the liquid), in excess
solute: a substance being dissolved in a solvent, does not settle to bottom
In a solution of calcium chloride and water, which is the solute?
1 2 3 4
0% 0%0%0%
1. Calcium chloride
2. Water3. Salt4. None of the
above
In a solution of isopropyl alcohol and potassium nitrate, which is the solvent?
1 2 3 4
0% 0%0%0%
1. Potassium nitrate
2. Isopropyl alcohol
3. Water4. None of the
above
Which of the following is a solution?
1 2 3 4
0% 0%0%0%
1. Salt water2. Sand and
water3. Oil and water4. All of the
above
In seltzer water, what is the solute?
1 2 3 4
0% 0%0%0%
1. Water2. Salt3. Oxygen gas4. Carbon dioxide
gas
Soluble: a substance that is able to be dissolved
Insoluble: a substance that is not able to be dissolved
How does the process of dissolving work?
Water is a “polar” molecule: It has a negative end and a positive end.
Most soluble compounds are ionic: they are made of positive ions and negative ions.
Let’s see what happens between these particles!
http://www.mhhe.com/physsci/chemistry/essentialchemistry/flash/molvie1.swf
http://www.kentchemistry.com/moviesfiles/Units/Kinetics/DissolutionofNaClinWater.htm
Factors Affecting Rate of Dissolution
Pre-Lab and Procedure Read-Through
Be ready to rock tomorrow!!
Homework
Unit 7 Packet p. 3: due tomorrow Read p. 4-5: by tomorrow; be
familiar with procedure! Did you turn in your Unit 6 Packet?!
Saturated: a solution with the maximum amount of dissolved solute
Unsaturated: a solution with less than the maximum amount of dissolved solute
Supersaturated: a solution with more than the maximum amount of dissolved solute Requires an increase then decrease of
temperature
A cup of water has just a pinch of salt stirred into it.
1 2 3 4
0% 0%0%0%
1. Saturated solution
2. Unsaturated solution
3. Supersaturated solution
4. None of the above
A candy maker adds excess sugar to a pot of water, boils the water until all the sugar dissolves, then allows the solution to cool. The sugar stays dissolved.
1 2 3 4
0% 0%0%0%
1. Saturated solution
2. Unsaturated solution
3. Supersaturated solution
4. None of the above
I stir sugar into my coffee just until no more will dissolve.
1 2 3 4
0% 0%0%0%
1. Saturated solution
2. Unsaturated solution
3. Supersaturated solution
4. None of the above
Demo – record your observations!
1. Solid sodium acetate (CH3COONa) is added to water in a test tube until there is more than will dissolve.
1. Making a “slurry”2. The test tube is heated over a flame until the
water boils and all the sodium acetate dissolves.
3. The test tube is allowed to cool in an ice bath.4. One crystal of sodium acetate is added to the
cooled test tube to precipitate the excess solute.
A: 28 March 2012
Take Out Unit 7 Packet page 3 Objective: You will be able to:
explore factors that affect the rate of dissolution.
Do now: Draw water molecules around each of these ions. Be sure each water molecule is oriented the correct direction!
+ –
A: Agenda
I. Do nowII. Demo: Dissolving a Salt Crystal
LatticeIII. Factors Affecting Rate of
Dissolution LabHomework: Finish pages 3-7: Thurs.
C: 29 March 2012 Take Out Unit 7 Packet page 3 Objective: You will be able to:
describe factors that affect the rate of dissolution and how they affect the rate of dissolution.
Do now: Draw water molecules around each of these ions. Be sure each water molecule is oriented the correct direction!+ –
C: Agenda
I. Do nowII. Factors Affecting Rate of
Dissolution LabIII. Reading: O2 in StreamsIV. Response to articleHomework: Pages 6-12: due Friday
Factors Affecting the Rate of Dissolution Lab
Rate of dissolution: How fast a solute dissolves in a solvent
5 min.
With your partner, complete the background questions on p. 4
Then, re-read the materials and procedure
Step 4 “Flicking” a test tube to mix
We’re actually going to “invert to mix.”
Watch the demo.
If your solutions take more than 30 minutes to dissolve, you can just write “30 min. +” for the time, and describe your observations.
Complete each step carefully!
Write thoughtful observations Answer all the questions neatly and
completely The biggest cause of low lab
averages is sloppy work on the analysis questions!
When you finish the lab
Clean up. Return all materials to the front table or wash and hang to dry.
Clean up splashes and paper towels! Begin to read and text-mark the
article on p. 8-9
Lab Behaviors
On task At your station Efficient but careful Precise:
Read and follow the procedure exactly. Collect careful data and observations.
Clean: Leave your area cleaner than you found it!
I put one spoonful of sugar in my coffee. It is a ______ solution.
1 2 3 4
0% 0%0%0%
1. Saturated2. Unsaturated3. Supersaturated4. Soluble
I put sugar in my coffee until no more will dissolve. It is a ____ solution.
1 2 3 4
0% 0%0%0%
1. Saturated2. Unsaturated3. Supersaturated4. Soluble
A solution with more than the maximum dissolved solute is a ____ solution.
1 2 3 4
0% 0%0%0%
1. Saturated2. Unsaturated3. Supersaturated4. Soluble
C: 30 March 2012
Take Out: p. 6-7 Objective: You will be able to:
describe factors affecting the solubility of solutes in water.
Do now: What three factors affect the rate of dissolution of a solid in a liquid?
Choose one factor and describe how it affects the rate of dissolution.
Agenda
1. Do now2. Lab questions and review?3. Exit ticket 7.14. O2 in Streams reading and
responseHomework: Pages 8-11: due MondayPage 12 due Thursday
Exit Ticket
When you finish your exit ticket, flip it over.
Then, begin reading the article on page 8, silently.
Problem: The power plant makes hot water to cool the equipment then they discharge it into the river
Hot water does not hold enough oxygen Since there is less oxygen the fish will dieIncrease in Algae Solution: we can add a steam pipe under the
Longfellow bridge move the steam throug a pipe to the other side of
the building where they will use it to heat up buildings o.o (brilliant)
5-10 years to build this-disturb wildlife-So much money O.o brainstorm--------------result accomplish goal
Read the article
Complete the questions on pages 10-11.
Then, we’ll get back together to discuss #8.
Communicate Your Position!
Groups of one to three people. Choose one of the options we
brainstormed. Sign up on the board. Meet with your group to plan out
what you’ll do to complete this assignment!
Due next Thursday!
A: 30 March 2012
Take Out: p. 10-11 Objective: You will be able to:
describe factors affecting the solubility of solutes in water.
Do now: From the article, what factor affects the solubility of a gas, like O2, in water? In what way does this factor affect the solubility of a gas in water?
Agenda
1. Do now2. Solubility Notes3. Reading a Solubility Curve4. O2 in Streams reading and
response5. Cave Video6. Molarity CalculationsHomework: Pages 12 and 15: due
Tuesday
Hot/warm water is discharge into local water ways in the Charles River and is killing fish/other living things in the river and is promoting algal blooms.
The hot water is caused by power plants using river water to cool their equipment
The solution is that the power plant is going to heat the water enough to create steam which is sent to heat big buildings in Boston.
C: 4 April 2012
Grab a calculator! Take Out Homework: Unit 7 Packet p. 10-11 Objective: You will be able to:
describe solubility of gases in solution and factors affecting their solubility.
make molarity calculations Do now: Calculate the molarity of a
solution made by dissolving 3.0 moles of solute in enough water to make 9.0 liters of solution.
Agenda
1. Do now2. Review 7.1 (rates of dissolution)3. Check homework p. 10-114. Respond to O2 in streams article – work
time5. Reading solubility graphs6. Molarity problems: unlock the code!Homework: Finish pages 15-16: Thurs.Response to article project due Mon.7.1 and 7.2 Quiz: Monday
Brainstorm p. 11
8. What ways could you communicate to others your position about something you’re passionate about?!
Communicate Your Position!
Groups of one to three people. Choose one of the options we
brainstormed. Sign up on the board. Meet with your group to plan out
what you’ll do to complete this assignment!
Due Monday!
Your response must…
Briefly summarize the article or indicate what the article is about
State your position on the change proposed by the power plant (to turn hot water discharge to steam to heat buildings across the Charles River)
Describe and support three reasons for your position.
Your response
This will obviously look VERY different for letters to the editor Tweets a Tumblr page A billboard A tshirt
Be creative! Do a high quality job!
This period…
Stay with your group and get most of the work done.
Check in with me at least once about your progress!
Return your computer by 2:20 pm
Track your Unit 6 Quiz and compile your unit 6 materials!
Solid in a liquid solvent
What factors affect solubility of a solid solute in a liquid solvent? (Not how fast it dissolves, but how
much of it can be dissolved.)
Solubility of Gases in Liquids
Temperature: solubility decreases as temperature increases Ex: Dissolved oxygen in lakes and rivers
Pressure: solubility increases as pressure increases Ex: Bottling soda
dilute: a volume of solution with a small amount of dissolved solute
concentrated: a volume of solution with a large amount of dissolved solute
concentration = amount of solute dissolved in a given quantity of solution.
)(_)(__)(
LvolumesolutionmolessoluteofamountMmolarity
VnM
Ex. 1
A chemist mixes 0.25 moles of sodium chloride into water to make 1.0 L of solution. Calculate the molarity.
Ex 2.
A saline (salt water) solution contains 0.90 g NaCl in exactly 100 mL of solution. What is the molarity of the solution?
Ex. 3
a) How many moles of solute are present in 1.5 liters of 0.24 M solution of sodium chloride?
b) How many grams is this?
Practice Problems
1. Calculate the molarity of 0.35 moles of sodium chloride dissolved in enough water to make 1.0 L of solution.
2. Calculate the molarity of 0.25 grams of NaCl in 100. mL of water.
3. a. How many moles of NaCl were used to make 500 mL of a 2.0 M solution?b. How many grams is that?
A: 3 April 2012
Take Out Homework: p. 15 Objective: You will be able to:
describe solubility of gases in solution and factors affecting their solubility.
Do now: Write two sentences to describe the change in solubility of solids and gases in water as temperature increases.
Agenda
1. Do now2. Review 7.1 (rates of dissolution)3. Check homework p. 154. Respond to O2 in streams articleHomework: Response to article due
Thurs.Bring an empty glass jar by Thurs!7.1 and 7.2 Quiz: Thurs.
Your response must…
Briefly summarize the article or indicate what the article is about
State your position on the change proposed by the power plant (to turn hot water discharge to steam to heat buildings across the Charles River)
Describe and support three reasons for your position.
Your response
This will obviously look VERY different for letters to the editor Tweets a Tumblr page A billboard A tshirt
Be creative! Do a high quality job!
This period…
Stay with your group and get most of the work done.
Check in with me at least once about your progress!
Track your Unit 6 Quiz and compile your unit 6 materials!
C: 5 April 2012
Grab a calculator! Take Out Homework: p. 15-16 Objective: You will be able to:
perform calculations involving the molarity of solutions.
Do now: Calculate the molarity of 2.0 moles of silver nitrate dissolved in enough water to make 4000. milliliters of solution. Use correct units! Show work.
Agenda
1. Do now2. Homework answers3. Making dilutions notes and examples4. Dilutions practice problems: unlock the
code!5. 7.2 “Exit” ticket6. Kook-aid lab day 1 CalculationsHomework: Read p. 20-23 for MondayQuiz Monday on 7.1 and 7.2Response to article project: due Monday
Making a Dilution
What if you have a solution of one concentration but need a solution of another concentration?
Dilute (verb): to make less concentrated by adding more solvent (water)
Stock solution: a concentrated solution kept in the lab “stock room”
M1V1=M2V2
Demo
Ex 1) Starting with our 0.02 M solution of CuCl2, how, how many milliliters of that do we need to make 100 mL of 0.01 M solution?
Example 2
How many milliliters of a 6.0 M stock solution would you need to make 100. mL of a 1.0 M solution?
Example 3
How many milliliters of an 18 M stock solution would you need to make 100 mL of a 6 M solution?
Practice Problems
1. How many grams of sugar (C12H22O11) do you need to make 400 mL of a 0.50 M solution?
2. How many milliliters of a 6.0 M stock solution would you need to make 500. mL of a 1.0 M solution?
3. How many milliliters of a 4.0 M stock solution would you need to make 500. mL of a 0.02 M solution?
Unlock the Code!
With your partner, complete page 17 Then, try the electronic lock to see if
you’re correct! If not, correct your work and try again!
Code = FIRST NONZERO DIGIT Round to two sig. figs! When you finish, have me initial p. 17,
and then read p. 20-22.
A: 5 April 2012
Grab a calculator! Take Out Homework: project Objective: You will be able to:
perform calculations involving the molarity of solutions and dilutions.
Do now: If you take 20 mL of a 6.0 M solution of HCl and dilute it to 100 mL, what is the new molarity?
Agenda
1. Do now2. Review 7.2 exit ticket3. 7.1 and 7.2 Quiz4. Kool-aid lab day 1 calculations and
demoHomework: Complete calculations on
pages 20-21.Read the procedure on page 21 and 22.
C: 9 April 2012
Grab a calculator! Take Out Homework: project (unless
you have emailed it!) Objective: You will be able to:
perform calculations involving the molarity of solutions and dilutions.
Do now: If you take 20 mL of a 6.0 M solution of HCl and dilute it to 100 mL, what is the new molarity?
Agenda
1. Do now2. Review 7.2 exit ticket3. 7.1 and 7.2 Quiz4. Kool-aid lab day 1 calculations and
demoHomework: Complete calculations on
pages 20-21.Read the procedure on page 21 and 22.
Quiz 7.1 and 7.2
When you finish your quiz, hand it in.
Track your Unit 6 Final Quiz on your Unit 6 Packet when you get them back.
Silently read p. 20-22 Complete all calculations on p. 20-
21. due Wednesday
Crime Scene Investigation
Your mission: to determine the time of death of the Kool-Aid man from a sample of Kool-Aid collected from him at the crime scene.
This period:
Read page 20 and do problem 1 Complete page 21, including
hypothesis #1 and 2 Read pages 22-23 due Wednesday: be ready to rock
when you come to class!
C: 11 April 2012
Take Out Homework: p. 20-21 Objective: You will be able to:
create a standard curve of transmittance of solutions of varying concentrations
Do now: Transmittance is how much light will pass through a sample of solution. Write a hypothesis on p. 21 relating concentration to transmittance.
Table p. 22
Test tube 1 2 3 4 5 6
Molarity (M) 0.00 0.40
Stock solution (mL)
0.0 8.0
Water (mL) 8.0 0.0
Total volume (mL)
8.0 8.0 8.0 8.0 8.0 8.0
Procedure
Steps 1-3: Make your 0.20 M stock solution of Kool-Aid
Steps 6-9: Make your series of diluted solutions.
Steps 10-14: Find and record the percent transmittance of each solution in the spectrophotometer.
Step 15: Graph and draw a line of best fit! Step 16-19: Find the concentration of the
solution collected from the crime scene and determine time of death.
Your goal
By the end of the period: Have a 0.20 M stock solution
prepared. Have pipetted your dilutions into
test tubes. Found and recorded their
transmittance in the spectrophotometer.
Homework: none!
C: 12 April 2012
Objective: You will be able to: create a standard curve of
transmittance of solutions of varying concentrations
determine the time of death of the Kool-Aid man!
Do now: Record qualitative observations of your series of solutions from yesterday on page 23.
Agenda
1. Do now2. Finish Kool-Aid Lab3. Graph data4. Determine concentration of unknown5. Answer analysis and conclusion6. Lab report infoHomework:Lab report due Weds. April 25
By the end of the period…
See the list on the board. This is due before you leave class
today – your graph and calculations are a 10 point lab grade!
No homework!
What you know…
Kool-Aid Man’s original concentration was 0.20 M at noon.
Children drank about half his volume in Kool-Aid each hour.
Each hour, he added enough water to fill himself back up.
What time did he die?
Clean up
1. Wash and return all your equipment to the kidney table
2. Return your unknown3. Work on the Analysis and ConclusionHomework: Line equation,Analysis and Conclusion Questions: due
tomorrowLab report due April 25
C: 13 April 2012
Grab a calculator Objective: You will be able to:
communicate your experiment and conclusions from the Kool-Aid Lab!
Do now: Pick up a rubric.
Agenda
I. Do nowII. Lab report requirementsIII. Determine goal(s)IV. Lab report work time!Homework: Lab report due Weds.
April 25 – printed and stapled, please!
Your goal today
Determine which parts of your lab report you will accomplish today.
You should choose challenging parts on which you might need my help!
For example, making the graph in Excel, summarizing the procedure, making a table, making a conclusion, etc.
In the computer lab…
Use your time wisely! Your screen must face the center of
the room! Ask questions! Save your work carefully in a place
where you can access it from home! Homework: Lab report due Weds.
April 25
C: 23 April 2012
Objective: You will be able to: describe four possible sources of
pollutants in Boston Harbor predict the products of a double
replacement reaction Do now: a. What type of reaction?b. Predict the products: NaBr(aq) + AgF(aq) → ____ + ____
Agenda
I. Do nowII. Lab report questions?III. Boston Harbor problemIV. Read articles and JigsawV. Double replacement reactions: p. 6-8
Homework: Lab report due Weds. April 25 – printed and stapled, please!
Finish pages 6-8: due Wednesday
Introduction to Project
Right now, as we speak, Boston Harbor is in trouble.
There is a pollutant in the water of the harbor that is killing large numbers of fish and causing state fisheries officials to worry for the health of the ecosystem for decades to come.
Already, over 1,000 fish have washed up dead on Boston’s beaches in the last month, with more expected to turn up in the coming weeks. Scientists are not sure what chemical is causing these deaths, only that they are not caused by the cold or other environmental factors.
Pollution Articles
Read the article assigned to you. Answer the questions at the end of
the article. Be prepared to describe what you
learn to your lab group members! If you finish early, choose any other
article to read.
Jigsaw
In your lab group, take turns describing to the other members of your group what you learned from your article.
Specifically, everyone needs to fill out the table on the front of the packet.
Chemical Source Effects How can we stop it?Lead
Copper
Potassium
Barium
If the ecosystem and economy of Boston Harbor is to survive this environmental catastrophe, it is up to YOU to figure out what chemical is poisoning the water, what the source of the chemical is, and what we can do to stop more of it from being released.
How?
There are some skills you’ll need to acquire first! How to predict the products of a
double replacement reaction. How to determine if the products
are soluble or insoluble in water. How to write a “net ionic
equation”
C: 25 April 2012
Take Out: Lab Report Objective: You will be able to:
predict the products of a double replacement reaction
predict the solubility of a product write net ionic equations
Do now: Write the correct formulas for:a. sodium sulfateb. calcium iodidec. lead (II) hydroxide
Agenda
I. Do nowII. Double replacement reactions answersIII. Predicting products, predicting
solubility and writing net ionic equations p. 6-13
Homework: Finish through page 13: due tomorrow!
What we have to know to be successful
How to predict the products of a double replacement reaction.
How to determine if the products are soluble in water (aq) or insoluble in water (s).
How to write a “net ionic equation” to show what’s really happening in a reaction!
This period
Work on pages 6-13 with your partner Page 9 mini-experiment: wear goggles Pages 10, 11 and 12 computer simulations:
go to the correctly labeled laptop Only up to four people at a time per laptop
station! Stay on task and work hard! Ask questions! Have me sign my initials at the bottom of
each page. 10 pt. classwork grade based on work ethic!
C: 27 April 2012
Take Out: Save Our Seas p. 14 Objective: You will be able to:
write a procedure to determine the identity of the unknown Boston Harbor pollutant!
Do now: What can you react with calcium iodide
to produce a precipitate? (Hint: Look at your solubility table on page 10.)
Agenda
I. Do nowII. Plan procedure: p. 15-18III. Create a data tableHomework: Finish through page 18
(procedure and data table) of the Save our Seas lab: due Monday
This period
With your lab group: Complete page 15-16 Use your first drafts of procedures written
by your group members to determine one awesome procedure for this lab.
Have me read and comment on your draft. Then, write a final draft in your packet! Finally, design a data table on p. 18
Materials
You can do as many reactions as you need to.
You can do reactions on a piece of plastic film or in spot plates.
You have dropper bottles of 14 different compounds (p. 16)!
GroupsObayannaCarlhebLorreno
CourtneyKendraCarlaAdleyDaysia
ChristineNekeyla
JesseDyani
MeryemBryan
MartelyLeslieKenny
PatrickJavierDevin
Jackson
Exit Ticket
Solutions of sodium bromide and lead (II) nitrate react.
1. Write the equation and predict the products.
2. Predict the solubility (s) or (aq) of the products.
3. Balance the equation.4. Write the ionic and net ionic
equations.
A: 26 April 2012
Take Out: “Save Our Seas” p. 14-15 Objective: You will be able to:
design a procedure to determine the identity of the Boston Harbor pollutant!
Do now: What can you react with calcium iodide to produce a precipitate? (Hint: Look at your solubility table on page 10.)
Agenda
I. Do nowII. Track exit ticketIII. Write a procedure to determine the
identity of the unknown!
Homework: none!
With your lab group…
1. Brainstorm how to determine the identity of the unknown pollutant.
2. Then, draft a procedure on notebook paper specific! chronological! describes what data to collect!
3. Finally, design a data table to collect your data and observations in tomorrow.
4. Due at the end of the period (one copy per group)
Groups
ZuriGarlynKarenAlerte
TraeJulianKayla
Loveng
LarissaBrunyrRicardoIsrael
EmilyMarie
SophieCrystalHannah
C: 30 April 2012
Objective: You will be able to: carry out your procedure to
determine the identity of the unknown Boston Harbor pollutant!
Do now: Solutions of calcium iodide and lead (II) nitrate react.
a. Write the molecular equation and balance it.
b. Then write the net ionic equation.
Agenda
I. Do nowII. Track 7.1 and 7.2 QuizIII. Write procedure final draftIV. Carry out your procedure and collect data!
Homework: Save our Seas: p. 19-21 due Thursday
Quiz on 7.3: Predicting products/net ionic equations: Thursday
Before you begin…
As a group, finish your rough draft and check in with me OR edit your rough draft and write the final draft on p. 17. What data will you collect? Where
will you record it? Design a beautiful data table to
record your data in on p. 18.
Once you start…
Goggles stay over your eyes! Only take one to three dropper
bottles at a time from the front table, and return them to where they belong when you finish with them.
Use 3 drops of each reactant every time – that’s completely enough!
A: 1 May 2012
Take Out: “Save Our Seas” p. 20 Objective: You will be able to:
draw conclusions about the pollutant in Boston Harbor
show what you know about predicting products of equations
Do now: Solutions of calcium iodide and lead (II) nitrate react.
a. Write the molecular equation and balance it.
b. Then write the net ionic equation.
Agenda
I. Do nowII. Track 7.1 and 7.2 Quiz and ReviewIII. 7.3 QuizIV. Draw conclusions and turn in
“Save Our Seas” packetHomework: None!
C: 3 May 2012
Grab a calculator and your clicker! Take Out: Save our Seas packet Objective: You will be able to:
Calculate the pH of a solution of a strong acid.
Do now: How many grams of potassium chloride (molar mass = 74.55 g/mol) are required to make 200. mL of a 0.60 M solution?
Agenda
I. Do now / quiz reviewII. 7.3 QuizIII. Acids and Bases NotesIV. Demo!V. Calculating pH from molarityVI. Practice ProblemsVII. Acid rain article and response Homework: Unit 7 packet p. 27-29: due
Monday do the bonus on a separate sheet of paper!
7.3 Quiz
Re-do 7.1 and 7.2 if you haven’t earned a 3 or 4 yet!
When you finish, make sure your “Save our Seas” packet is complete, and turn it in!
Then, complete pages 28-29 in the Unit 7 Packet
If you leave your Unit 7 packet out, I’ll stamp it!
Properties of Acids
SourTurn universal indicator redReact with metal to produce H2
React with bases to produce salt and water
Electrolyte
Properties of bases
BitterTurn universal indicator blueSlipperyReact with acids to produce salt and waterElectrolyte
pH pH is a
measurement of how acidic or basic a solution is
0-14 scale 0 is most acidic 14 is most basic 7 is neutral
(water)
Bleach is a cleaning product that feels slippery. It is
1 2 3
0% 0%
100%1. An acid2. A base3. Neutral
pH and acids
The numbers on the pH scale come from the hydrogen ion concentration [H+] pH = “Power of Hydrogen”
Acid: a compound that dissolves in water to produce a hydrogen ion (H+)
The higher the hydrogen ion concentration, the LOWER the pH!
Let’s test pH
To test pH we can use pH paper or a pH probe
Substance pHvinegar 2
distilled water 6
tap water 7
HCl 1
bleach 8
MOM 9
soap 7
ammonia 11
baking soda 8
NaOH 12
Linear Scale
Linear scale – y value changes at a constant rate with changes in the x value (straight line on a graph)
Example: The salary for a government employee changes by a set amount each year
Linear Scale
0 2 4 6 8 10 120
10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
Salary by Year
Year
Sala
ry in
Dol
lars
Logarithmic scale
Logarithmic scale – y value increases by being multiplied by 10 (curved line)
The pH scale is a logarithmic scale Example: A solution with a pH of 6 is
10 times more acidic than a pH of 7 – it has 10 times more hydrogen ions in it
Earthquake!
Richter scale – 1-10 based on magnitude of the earthquake
So two magnitude 5’s should add up to a 10, right? (according to a CA politician…)
Only if it is linear (which it isn’t!) A category 6 is TEN times stronger
than a category 5, so you need TEN 5’s to make the same energy as a 6
So a 9 is 100,000 times stronger than a 5!!
A solution with a pH of 3 is ___ times more acidic than a solution with a pH of 4.
1 2 3 4
0%
16%
79%
5%
1. 12. 23. 104. 100
A solution with a pH of 3 is ___ times more acidic than a solution with a pH of 5.
1 2 3 4
0%
72%
28%
0%
1. 22. 103. 204. 100
A: 3 May 2012
Take Out: Unit 7 Packet p. 27 Objective: You will be able to:
differentiate between a strong and weak acid
Do now: Calculate the concentration of [OH-] ions in a solution with a pH of 11.
Agenda
I. Do now II. Homework AnswersIII. Strong vs. Weak AcidsIV. Acid rain article and responseHomework: Unit 7 Packet p. 30
(background questions) and Read lab procedure on p. 31: Tuesday
Where does pH come from?
A strong acid is added to water: http://www.mhhe.com/physsci/chemi
stry/essentialchemistry/flash/acid13.swf
HCl(aq) → H+(aq) + Cl-(aq) Dissociation!
pH Problems!
1.2x10-3 grams of HCl is dissolved in 2 L of water. Calculate the pH.
1.12x10-9 grams of KOH is dissolved in 100 mL of water. Calculate the pH.
2.32x10-5 grams of Mg(OH)2 is dissolved in 100 mL of water. Calculate the pH.
Strong vs. Weak Acids
HCl H+ + Cl-
Hydrochloric acid is an example of a strong acid. It will dissociate completely, maximizing the amount of H+ for a given concentration of acid.
No HCl will be present.
HC2H3O2 H+ + C2H3O2- Acetic acid is an
example of a weak acid. It will not dissociate completely, leaving most of the solution to contain HC2H3O2
List of strong acids and basesAcid BaseHI LiOHHBr NaOHHClO4 KOH
HCl RbOHH2SO4 CsOH
HNO3 Mg(OH)2
HClO3 Ca(OH)2
Sr(OH)2
Ba(OH)2
Acid Rain Article
1. Independently, read the article on p. 28
2. Then, complete the questions on p. 29
3. If you finish early, do the BONUS on a separate sheet of paper and hand it in!
4. Then, begin your homework: Unit 7 Packet p. 30 (background
questions) and read lab procedure on p. 31: Tuesday
Calculating pH
pH = −log[H+] Negative log of the concentration of
hydrogen ions. The more hydrogen ions, the lower
the pH!
Examples and Problems
1. In a neutral solution, the concentration of hydrogen ions is 1x10-7 M. Calculate the pH.
2. Calculate the pH of a 0.001 M H+ solution.
3. What is the pH of a solution with a hydrogen ion concentration of 1.0x10-10?
4. Calculate the pH of a solution where [H+] = 5.0x10-6
What about bases?
Strong bases produce OH- ions in a solution.
NaOH(aq) → Na+(aq) + OH-(aq) pOH = –log[OH-] pH + pOH = 14
Examples and Problems
1. What is the pH of a solution if [OH-] = 4.0x10-11 M?
2. Calculate the pH of a solution if [OH-] = 4.3x10-5 M.
3. [OH-] = 2.0x10-5 M
Extension
1. What is the concentration of hydrogen ions in a solution with pH = 8?
2. What is the concentration of hydrogen ions in a solution with pH = 2.35?
3. What is the concentration of hydroxide ions in a solution with pH = 10?
4. What is the concentration of hydrogen ions in a solution with pH = 9.50?
Assignment
With your partner: Unit 7 Packet p. 27: Calculating
pH Independently:
Unit 7 Packet p. 28-29: Acid rain article and reading questions
due at the end of the period!
C: Homework
Unit 7 packet p. 27-29: due Monday do the bonus on a separate sheet
of paper! Complete that table by showing
persistence and grit!
8 May 2012
Grab a calculator! Objective: You will be able to:
calculate the freezing point of a solution given solute concentration.
1. Do now: a. Calculate the pH of a 0.40 M solution of HCl.b. Calculate the pH of a solution of 0.0020 M NaOH.
Agenda
I. Do nowII. pH practiceIII. 7.4 Exit TicketIV. Colligative Properties!V. Hand back work and organizeHomework: Finish Colligative
Properties worksheet: due tomorrow
Colligative Properties
http://antoine.frostburg.edu/chem/senese/101/solutions/faq/why-salt-melts-ice.shtml
Does adding solute to water change the boiling or freezing point of water?
With your partner
Work through the Colligative Properties worksheet.
Complete it for homework: due tomorrow…because….
Bring (Optional)
If you’d like mix-ins or toppings, please bring them!
You probably also want to bring a pair of gloves.
Homework
Finish Colligative Properties handout (all pages!): due tomorrow
Bring mix-ins and gloves (optional)
21 March 2011
Take Out: Lab Handout Objective: SWBAT prepare for lab
by writing an objective and summarizing the procedure.
Do now: Write an equation for the reaction between solutions of HBr and KOH.
Agenda
I. Do nowII. Homework checkIII. Strong vs. weak acidsIV. Pre-lab: writing an objective and
summarizing the procedureV. Begin lab (?)Homework: Finish “Titration Pre-
Lab” Handout
With your lab group… Complete the “Titration Pre-Lab”
handout to be ready for lab tomorrow.
Be sure you have finished the front page of the lab handout by tomorrow.
11 May 2012
Grab your goggles! Objective: You will be able to:
react a strong acid with a strong base to observe changes in pH.
Do now: Write the molecular and net ionic equation for the reaction between solutions of HBr and KOH.
Agenda
I. Do nowII. Mr. Purser: Pre-lab review and practiceIII. Pre-lab discussion and questionsIV. Complete labV. Work on Conclusions questionsHomework: Finish Unit 7 Packet p. 30-36: due
Tues.Review sheet p. 1-2: Mastery and Prioritization:
due Tues.Lab corrections due by next Friday.
Acids and Bases Lab
We will be reacting a strong acid (HCl) with a strong base (NaOH).
1. What happens when you put a strong acid or a strong base in water?
2. What happens when you react HCl with NaOH? Write an equation.
Pre-lab
Collect materials from the front of the room, and begin to carry out the procedure.
Return the bromothymol blue indicator as soon as you have added your one drop.
Collecting Data
Stir after every drop! After the first few, and then every few,
drops you will be using pH paper to record pH.
Use a toothpick to drop a tiny bit of your solution onto the pH paper. Don’t stick the pH paper into your
solution! Record pH color and pH often, as well
as the color of the solution itself
Conclusions
Carefully and thoughtfully answer the conclusions questions with your group.
p. 30-36 These are due Tuesday.
Safety
We are working with a strong acid with a concentration of 0.1 M and a strong base with concentration 0.1 M.
Wear goggles. Work carefully and precisely, following
directions exactly. Wipe up spills with a dry paper towel
and then clean with a wet sponge. Stay seated whenever possible to avoid
spills.
Clean up
Wash out your spot plate with your goggles on.
Return equipment to the front table. Throw away pH paper (don’t leave it
in the sink!)
Homework
Finish Unit 7 Packet p. 30-36: due Tues.
p. 32 #4: Use the number of drops of HCl when the solution was neutralized (NOT the number of drops after you added 5 additional drops!)
Review sheet p. 1-2: Mastery and Prioritization: due Tues.
C: 10 May 2012
Take Out: Unit 7 Packet p. 40-41 Objective: SWBAT demonstrate freezing
point depression by making (and eating) ice cream!
Do now: Use your Colligative Properties handout to determine:
a) Increasing the number of particles of solute will ______ the freezing point of a solution.
b) Name one compound that will cause a greater decrease in freezing point than NaCl. Explain why you chose that compound.
Agenda
I. Do nowII. Colligative Properties answersIII. Track and go over exit ticketIV. Pre-lab and directionsV. Make ice cream!VI. Eat ice creamVII. Clean up and post labHomework: Lab Analysis/Conclusions: due
tomorrow7.4 and 7.5 Quiz tomorrow
Colligative Properties
Properties of a solution (like melting point and freezing point) that depend on the number of particles and concentration of the solute.
Ice cream lab directions
Station 1: Ice cream mixture In a small ziploc bag:
1 c. milk¼ c. sugar¼ t. vanillamix-ins you brought
Push out all the air and seal the bag Fold the top over and seal with
masking tape
Station 2: Salt and Ice In a large ziplog bag:
¾ full with ice 200 mL water
Take the temperature and record it Add 145 g salt
Part III: At your table: Place the small bag inside the
large bag of ice, push out the air and seal the bag.
Place the first big bag in a second big bag, push out the air and seal it.
Shake and knead vigorously! When the ice cream has solidified,
take the temperature of the ice water again
Eat your ice cream!
Put your ice cream into cups, add toppings and enjoy!
Clean up (When you have cleaned, raise your hand, and I will come sign your sheet) Small bag, cups and spoons go in the
trash Large bags get emptied out and
placed into the front sink to be reused Work on Data and Analysis, and
Conclusions
The ice cream mixture has lots of dissolved solutes, so it won’t melt unless it is well below 0oC.
How does it work?
Ice has to absorb heat energy in order to melt.
Where does that heat energy come from?
Adding salt lowers the melting point of the ice, so it must absorb even more heat energy (from the ice cream mixture) to melt.
This makes the ice/water/salt solution even colder than plain ice water.
This super cold solution brings the temperature of the ice cream mixture to below freezing, to freeze the ice cream.
Heat Energy
Exit Ticket 7.5
When you finish, turn it in. Then, work on the ice cream lab
analysis and conclusion questions on p. 44 of the Unit 7 Packet
C: 11 May 2012
Take Out: Unit 7 Packet p. 44 Objective: SWBAT
review Unit 7 objectives Do now: Calculate the pH of a 0.002
M solution of KOH.
Agenda
I. Do nowII. Go over ice cream post-labIII. Review all Unit 7 objectives
Homework: Unit 7 quiz Monday - all objectives
Review packet p. 1-2: Mastery and Prioritize
Review Stations
Write your work and answers on a lined sheet of paper
Work efficiently and with only the people in your group.
Please wait to move until the timer goes off!