Chemistry I Chemistry I Mr. CrupiMr. Crupi

Colonial High SchoolColonial High School

Unit: Matter- Properties and ChangeUnit: Matter- Properties and Change2.1 - Properties of Matter2.2- Changes in Matter2.3- Mixtures of Matter

2.4- Elements and Compounds

Examining MatterExamining Matter

When examining matter, it helps to When examining matter, it helps to deal with deal with pure substancespure substances

A A pure substancepure substance is made up of only is made up of only one type of matterone type of matter

ElementsElements are pure substances- they are pure substances- they are made of only one kind of atomare made of only one kind of atom

CompoundsCompounds are pure substances- are pure substances- they are made of one kind of they are made of one kind of molecule or formula unitmolecule or formula unit

Examples:Examples:

IronIron is a pure substance- made only is a pure substance- made only of iron atomsof iron atoms

SugarSugar is a pure substance- composed is a pure substance- composed only of sugar moleculesonly of sugar molecules

AirAir is not a pure substance- it is a is not a pure substance- it is a mixture of different gasesmixture of different gases

Properties of MatterProperties of Matter

Matter can be described by two kinds Matter can be described by two kinds of properties: of properties: Physical PropertiesPhysical Properties or or Chemical PropertiesChemical Properties

Physical propertiesPhysical properties are observable are observable without changing the composition of without changing the composition of the substancethe substance

Chemical propertiesChemical properties are only are only observable when the composition of observable when the composition of the substance changesthe substance changes

Examples:Examples:

ColorColor is a physical property is a physical property FlammabilityFlammability is a chemical property is a chemical property FlexibilityFlexibility is a physical property is a physical property ReactivityReactivity with acids is a chemical with acids is a chemical

propertyproperty

More on propertiesMore on properties

Physical and chemical properties can Physical and chemical properties can be either be either intensiveintensive or or extensiveextensive

Intensive propertiesIntensive properties do not change do not change depending on the amount of matter depending on the amount of matter

Extensive propertiesExtensive properties change change depending on the amount of matterdepending on the amount of matter

Examples:Examples:

ColorColor is an intensive property is an intensive property MassMass is an extensive property is an extensive property VolumeVolume is an extensive property is an extensive property Reactivity with acidsReactivity with acids is an intensive is an intensive

propertyproperty

Properties- More ExamplesProperties- More Examples

Matter can exist in three common Matter can exist in three common states:states:

SolidSolid- Matter with a definite shape and - Matter with a definite shape and definite volumedefinite volume

LiquidLiquid- Matter with an indefinite shape but - Matter with an indefinite shape but definite volumedefinite volume

GasGas- Matter with an indefinite shape and - Matter with an indefinite shape and volumevolume

Liquids and Gases are Liquids and Gases are fluidsfluids. (fluids flow). (fluids flow) VaporVapor is the gaseous state of a substance is the gaseous state of a substance

that is solid or liquid at room temperaturethat is solid or liquid at room temperature

Solids/Liquids/GasesSolids/Liquids/Gases

Types of changesTypes of changes

Matter can undergo two types of Matter can undergo two types of changes- changes- Physical changesPhysical changes or or chemical changeschemical changes

Physical changesPhysical changes do not change the do not change the composition of the substancecomposition of the substance

Chemical changesChemical changes change the change the composition of a substancecomposition of a substance

ExamplesExamples

BurningBurning is a chemical change is a chemical change MeltingMelting is a physical change is a physical change Shattering a glassShattering a glass is a physical is a physical

changechange Reacting with acidReacting with acid is a chemical is a chemical

changechange

The Law of conservation of massThe Law of conservation of mass

All matter obeys All matter obeys the law of the law of conservation of massconservation of mass

The law of conservation of massThe law of conservation of mass states that in a chemical or physical states that in a chemical or physical change, matter is neither created nor change, matter is neither created nor destroyeddestroyed

The law of conservation of massThe law of conservation of mass

Some sample problemsSome sample problems

If 14.0 grams of Nitrogen are reacted with If 14.0 grams of Nitrogen are reacted with 3.0 grams of Hydrogen to form ammonia, 3.0 grams of Hydrogen to form ammonia, calculate the mass of ammoniacalculate the mass of ammonia

14 g N + 3 g H = 17 g ammonia14 g N + 3 g H = 17 g ammonia If 16.0 grams of Oxygen are reacted with If 16.0 grams of Oxygen are reacted with

Carbon to form 22.0 grams of Carbon Carbon to form 22.0 grams of Carbon Dioxide, calculate the mass of Carbon Dioxide, calculate the mass of Carbon usedused

16.0 g O + x g C = 22.0 g CO16.0 g O + x g C = 22.0 g CO22

C = 6.0 gC = 6.0 g

MixturesMixtures

Matter is rarely found as pure Matter is rarely found as pure substances. More often than not, it is substances. More often than not, it is in a in a mixturemixture

MixturesMixtures are combinations of two or are combinations of two or more substances in which each more substances in which each substance retains its chemical substance retains its chemical properties. Can be separated properties. Can be separated physically.physically.

Types of MixturesTypes of Mixtures

There are two types of mixtures:There are two types of mixtures: Homogeneous mixtures-Homogeneous mixtures- mixtures mixtures

with constant composition with constant composition throughoutthroughout

Heterogeneous mixtures-Heterogeneous mixtures- One One without a constant composition without a constant composition throughout.throughout.

Examples of Homogeneous Examples of Homogeneous mixturesmixtures

Kool-AidKool-AidTap WaterTap WaterGasolineGasolineHomogeneous Homogeneous mixtures are also mixtures are also calledcalled solutions solutions

Examples of Heterogeneous Examples of Heterogeneous MixturesMixtures

PizzaPizzaMuddy WaterMuddy WaterA RatA Rat

Separating MixturesSeparating Mixtures There are There are

various ways various ways to separate to separate mixturesmixtures

Colored Colored candies could candies could be separated be separated manuallymanually

Separating MixturesSeparating MixturesMixtures Mixtures of solids of solids in liquids in liquids can be can be filteredfiltered

Separating MixturesSeparating Mixtures Mixtures of liquids in liquids can be Mixtures of liquids in liquids can be

distilleddistilled DistillationDistillation involves boiling away one of involves boiling away one of

the liquidsthe liquids CrystallizationCrystallization separates solids that are separates solids that are

dissolved in liquidsdissolved in liquids ChromatographyChromatography separates dissolved separates dissolved

substances by their mobilitysubstances by their mobility

ElementsElements

An An ElementElement is a pure substance is a pure substance that cannot be separated into that cannot be separated into simpler substances by physical or simpler substances by physical or chemical meanschemical means

All of the known elements are All of the known elements are listed on the periodic tablelisted on the periodic table

HH HeHe

LiLi BeBe BB CC NN OO FF NeNe

NaNa MgMg AlAl SiSi PP SS ClCl ArAr

KK CaCa ScSc TiTi VV CrCr MnMn FeFe CoCo NiNi CuCu ZnZn GaGa GeGe AsAs SeSe BrBr KrKr

RbRb SrSr YY ZrZr NbNb MoMo TcTc RuRu RhRh PaPa AgAg CdCd InIn SnSn SbSb TeTe II XeXe

CsCs BaBa LaLa HfHf TaTa WW ReRe OsOs IrIr PtPt AuAu HgHg TlTl PbPb BiBi PoPo AtAt RnRn

FrFr RaRa AcAc RfRf DbDb SgSg BhBh HsHs MtMt RgRg DsDs UubUub UutUut UuqUuq UupUup UuhUuh UusUus UuoUuo

CeCe PrPr NdNd PmPm SmSm EuEu GdGd TbTb DyDy HoHo ErEr TmTm YbYb LuLu

ThTh PaPa UU NpNp PuPu AmAm CmCm BkBk CfCf EsEs FmFm MdMd NoNo LrLr

Periodic TablePeriodic TableThe periodic table is The periodic table is

organized by organized by increasing mass in increasing mass in rows calledrows called periods.periods.

HH HeHe

LiLi BeBe BB CC NN OO FF NeNe

NaNa MgMg AlAl SiSi PP SS ClCl ArAr

KK CaCa ScSc TiTi VV CrCr MnMn FeFe CoCo NiNi CuCu ZnZn GaGa GeGe AsAs SeSe BrBr KrKr

RbRb SrSr YY ZrZr NbNb MoMo TcTc RuRu RhRh PaPa AgAg CdCd InIn SnSn SbSb TeTe II XeXe

CsCs BaBa LaLa HfHf TaTa WW ReRe OsOs IrIr PtPt AuAu HgHg TlTl PbPb BiBi PoPo AtAt RnRn

FrFr RaRa AcAc RfRf DbDb SgSg BhBh HsHs MtMt RgRg DsDs UubUub UutUut UuqUuq UupUup UuhUuh UusUus UuoUuo

CeCe PrPr NdNd PmPm SmSm EuEu GdGd TbTb DyDy HoHo ErEr TmTm YbYb LuLu

ThTh PaPa UU NpNp PuPu AmAm CmCm BkBk CfCf EsEs FmFm MdMd NoNo LrLr

Periodic TablePeriodic TableElements with similar Elements with similar

properties are in the properties are in the same column, called same column, called groupsgroups or or familiesfamilies..

CompoundsCompounds

Elements combine with each other Elements combine with each other chemically to form chemically to form compoundscompounds

A A compoundcompound is a combination of is a combination of two or more different elements two or more different elements combined chemicallycombined chemically

ExamplesExamples Sodium chloride: Sodium chloride: NaCl NaCl is a is a

compound made of 1 sodium atom compound made of 1 sodium atom and 1 chlorine atomand 1 chlorine atom

Calcium Carbonate: Calcium Carbonate: CaCOCaCO33 is a is a compound made of 1 calcium compound made of 1 calcium atom, 1 carbon atom, and 3 atom, 1 carbon atom, and 3 oxygen atomsoxygen atoms

How many of each atom are in How many of each atom are in Aluminum sulfateAluminum sulfate: : AlAl22(SO(SO44))33??

The Law of Definite ProportionsThe Law of Definite Proportions

All compounds obey the All compounds obey the law of law of definite proportionsdefinite proportions

The law of definite proportions The law of definite proportions states that a compound, no matter states that a compound, no matter how much of it you have, always how much of it you have, always has the same ratio of elements has the same ratio of elements composing it.composing it.

The Law of Definite ProportionsThe Law of Definite Proportions

If samples of matter have different ratios If samples of matter have different ratios of elements, they are different of elements, they are different compoundscompounds

To calculate the percent by mass of an To calculate the percent by mass of an element in a compound, you use the element in a compound, you use the following formula:following formula:

%100compound of mass

element of massmassby Percent

ExampleExample

Calculate the percent by mass of each Calculate the percent by mass of each element in element in aluminum chloridealuminum chloride, , AlClAlCl33

%76.79100%133.33

106.35%Cl

%24.20100%133.33

26.98%Al

compound of mass 133.33106.35335.45Cl

26.98126.98Al

The Law of multiple proportionsThe Law of multiple proportions

The law of multiple proportionsThe law of multiple proportions states that when elements form states that when elements form compounds, they always combine compounds, they always combine in simple whole number ratiosin simple whole number ratios

Example: Example: HH22OO ( (WaterWater): 2 hydrogens ): 2 hydrogens to 1 oxygen to 1 oxygen HH22OO22 ((Hydrogen PeroxideHydrogen Peroxide) 2 ) 2 hydrogens to 2 oxygenshydrogens to 2 oxygens