MATTERMATTER

Chapter 3Chapter 3

Definitions from Matter TreeDefinitions from Matter Tree Matter – anything that has space or takes Matter – anything that has space or takes

up volumeup volume

Mixture – 2 or more materials NOT Mixture – 2 or more materials NOT chemically combinedchemically combined

MixturesMixtures Heterogeneous – mixtures composed of more Heterogeneous – mixtures composed of more

than one phasethan one phase Ex: oil and waterEx: oil and water Ex: graniteEx: granite

Homogeneous – mixtures consisting of one phaseHomogeneous – mixtures consisting of one phase Each piece has the same propertiesEach piece has the same properties Ex: air, Kool-AidEx: air, Kool-Aid Another name for a homogeneous mixture is Another name for a homogeneous mixture is

SOLUTIONSOLUTION

Pure SubstancePure Substance Always has the same compositionAlways has the same composition

ElementElement – substance composed of only – substance composed of only one kind of atomone kind of atom Ex: Ex: S, Ca, O, He, NS, Ca, O, He, N

CompoundCompound – Substances composed of 2 or more – Substances composed of 2 or more elements chemically combinedelements chemically combinedex: Water, salt, hydrochloric acidex: Water, salt, hydrochloric acid

Physical PropertiesPhysical Properties Properties of a substance that can be Properties of a substance that can be

observed WITHOUT changing the substanceobserved WITHOUT changing the substance Ex: Length, color, temp.Ex: Length, color, temp.

Two types of Physical PropertiesTwo types of Physical Properties IntensiveIntensive – DOES NOT depend on the size of the sample – DOES NOT depend on the size of the sample

Ex: color, malleability, ductility, conductivity, MP, BP, Ex: color, malleability, ductility, conductivity, MP, BP, densitydensity

Extensive – Extensive – DOES depend on the size of the sampleDOES depend on the size of the sampleEx: mass, length, volumeEx: mass, length, volume

Chemical PropertiesChemical Properties Describes the behavior of a substance Describes the behavior of a substance

undergoing a chemical changeundergoing a chemical change Ex: Cl reacts with Na Ex: Cl reacts with Na NaCl NaCl Ex: Fe + OEx: Fe + O22 Fe Fe22OO33 (rust) (rust)

Physical ChangesPhysical Changes Change that DOES NOT result in a new Change that DOES NOT result in a new

substance being formedsubstance being formed

Ex: Cutting, dissolving sugar in HEx: Cutting, dissolving sugar in H22O, phase O, phase changeschanges

Chemical ChangesChemical Changes Changes that produce a new substanceChanges that produce a new substance

Ex: Rust, CuClEx: Rust, CuCl22 + Al foil + Al foil

EnergyEnergy Physical and chemical changes are always Physical and chemical changes are always

accompanied by energy changesaccompanied by energy changes

Most common form of energy involves Most common form of energy involves heatheat

Types of HeatTypes of Heat Endothermic – absorbs heatEndothermic – absorbs heat

Exothermic – releases heatExothermic – releases heat

Calculating HeatCalculating Heat

Q = mCQ = mC∆T∆TWhere: Q = heat (Joules or calories)Where: Q = heat (Joules or calories)

m = mass (g)m = mass (g)C = specific heat (J/g C = specific heat (J/g ooC)C)∆∆T = change in temp(T T = change in temp(T finalfinal – T – T

initialinitial) )

Calculating HeatCalculating HeatHow much heat is lost when 25.6g of How much heat is lost when 25.6g of

water cools from 87.4 water cools from 87.4 ooC to 34.5 C to 34.5 ooC?C?

Calculating HeatCalculating HeatAluminum has a specific heat of 0.97 Aluminum has a specific heat of 0.97

J/g J/g ooC. 30,006 J of heat are added to C. 30,006 J of heat are added to change the substance from 67.3 change the substance from 67.3 ooC C to 87.2 to 87.2 ooC. What is the mass?C. What is the mass?

Calculating HeatCalculating HeatWhat is the final temperature of 33.3 g What is the final temperature of 33.3 g

of water when 67,456 J of heat are of water when 67,456 J of heat are added at 55.3 added at 55.3 oo C? C?

Calculating HeatCalculating HeatHow many calories of heat are needed How many calories of heat are needed

to change 98g of water 12 to change 98g of water 12 ooC?C?