CHAPTER 6CHAPTER 6

CONCURRENT ENROLLMENTCONCURRENT ENROLLMENT

MATTERMATTER Solids have a definite shape Solids have a definite shape Liquids will have the shape of the container, it will Liquids will have the shape of the container, it will

not always fill the containernot always fill the container Gases will have the shape of the container, it will Gases will have the shape of the container, it will

always fill the containeralways fill the container CompressibilityCompressibility

– The change in volume of a sample resulting The change in volume of a sample resulting from a pressure changefrom a pressure change

– Occurs only in gasesOccurs only in gases Thermal expansionThermal expansion

– The change in volume of a sample due to a The change in volume of a sample due to a change in temperaturechange in temperature

KINETIC THEORYKINETIC THEORY Kinetic energyKinetic energy

– The energy a particle has when it is in motionThe energy a particle has when it is in motion– KE = 1/2mvKE = 1/2mv22

Kinetic theoryKinetic theory– Matter is composed of tiny particles called moleculesMatter is composed of tiny particles called molecules– The particles are in constant motion (have kinetic energyThe particles are in constant motion (have kinetic energy– The particles have potential energy as a result of attracting The particles have potential energy as a result of attracting

or repelling each otheror repelling each other– The average particle speed increases as the temperature The average particle speed increases as the temperature

increasesincreases– The particles transfer energy form one to another during The particles transfer energy form one to another during

collisions in which no net energy is lost from the systemcollisions in which no net energy is lost from the system Potential energyPotential energy

– The energy a particle has when it is at restThe energy a particle has when it is at rest

CONTINUEDCONTINUED Cohesive forceCohesive force

– Attractive force between particlesAttractive force between particles Disruptive forceDisruptive force

– Force resulting from particle motionForce resulting from particle motion SolidSolid

– high density (particles close together), definite shape, small high density (particles close together), definite shape, small compressibility (particles are so close they cannot be pushed compressibility (particles are so close they cannot be pushed together), very small thermal expansiontogether), very small thermal expansion

LiquidLiquid– High density (particles close together), indefinite shape, small High density (particles close together), indefinite shape, small

compressibility (particles are close, cannot be pushed together), compressibility (particles are close, cannot be pushed together), small thermal expansionsmall thermal expansion

GasGas– Low density (particles widely separated), indefinite shape, large Low density (particles widely separated), indefinite shape, large

compressibility (mostly empty space, they can be pushed together), compressibility (mostly empty space, they can be pushed together), moderate thermal expansionmoderate thermal expansion

GAS LAWSGAS LAWS Mathematical relationship that describes the Mathematical relationship that describes the

behavior of gasesbehavior of gases PressurePressure

– How often the gas particles hit the wall and each otherHow often the gas particles hit the wall and each other– Force per unit area of surface, measured in atmospheric Force per unit area of surface, measured in atmospheric

pressurepressure

Standard pressureStandard pressure– 1 atm or 760 mmHg of mercury or 760 torr1 atm or 760 mmHg of mercury or 760 torr

Absolute zeroAbsolute zero– Where all motion stops, a value of 0 on the Kelvin scale, Where all motion stops, a value of 0 on the Kelvin scale,

different from Celsius by 273different from Celsius by 273

COMBINED GAS LAWSCOMBINED GAS LAWS Boyle’s lawBoyle’s law

– Law that describes the pressure and volume behavior of Law that describes the pressure and volume behavior of a gas at constant temperaturea gas at constant temperature

Charles’s lawCharles’s law– Law that describes the temperature and volume Law that describes the temperature and volume

behavior of a gas at constant pressurebehavior of a gas at constant pressure

Combined gas lawCombined gas law– Law the describes the pressure, volume, and Law the describes the pressure, volume, and

temperature behavior of a gas at constant molestemperature behavior of a gas at constant moles

– PP11VV11 = = PP22VV22

TT11 T T2 2

– All other laws can be found in this equation All other laws can be found in this equation

IDEAL GAS LAWIDEAL GAS LAW Avogadro’s lawAvogadro’s law

– Equal volumes of gases measured at the same Equal volumes of gases measured at the same temperature and pressure contain equal temperature and pressure contain equal numbers of moleculesnumbers of molecules

Standard conditions (STP)Standard conditions (STP)– 1.00 atm and 01.00 atm and 0 o oCC

Ideal gas lawIdeal gas law– PV = nRTPV = nRT– P = pressure (in atm); V = volume (in L); n = P = pressure (in atm); V = volume (in L); n =

number of moles; R = constant, 0.0821 number of moles; R = constant, 0.0821 LL..atm/molatm/mol..K; T = temperature (in Kelvin) K; T = temperature (in Kelvin)

DALTONS AND GRAHAM’S LAWDALTONS AND GRAHAM’S LAW Partial pressurePartial pressure

– Total pressure exerted by a mixture of gases is equal to Total pressure exerted by a mixture of gases is equal to the sum of all the partial pressuresthe sum of all the partial pressures

EffusionEffusion– A process in which a gas escapes form a container A process in which a gas escapes form a container

through a small holethrough a small hole

DiffusionDiffusion– A process that causes gases to spontaneously A process that causes gases to spontaneously

intermingle when they are brought togetherintermingle when they are brought together

Graham’s lawGraham’s law– Effusion rate AEffusion rate A = = (molecular mass of B)(molecular mass of B)1/21/2

Effusion rate B (molecular mass of A)Effusion rate B (molecular mass of A)1/21/2

EVAPORATION AND BOILINGEVAPORATION AND BOILING EvaporationEvaporation

– Endothermic process to change a liquid into a gasEndothermic process to change a liquid into a gas CondensationCondensation

– Exothermic process in which a gas changes into a liquidExothermic process in which a gas changes into a liquid Vapor pressureVapor pressure

– Pressure exerted by vapor that is in equilibrium with its Pressure exerted by vapor that is in equilibrium with its liquidliquid

– Molecular mass and how polar a compound is will affect Molecular mass and how polar a compound is will affect the vapor pressurethe vapor pressure

– Smaller masses and nonpolar compounds have more Smaller masses and nonpolar compounds have more vapor pressurevapor pressure

Boiling pointBoiling point– Temperature at which the vapor pressure of a liquid is Temperature at which the vapor pressure of a liquid is

equal to the atmospheric pressureequal to the atmospheric pressure– Boiling points can be raised by increasing pressureBoiling points can be raised by increasing pressure

SUBLIMATIONSUBLIMATION Endothermic process where a solid converts to a gas without Endothermic process where a solid converts to a gas without

going through the liquid phasegoing through the liquid phase Carbon dioxide or iodine solidCarbon dioxide or iodine solid Melting pointMelting point

– Temperature at which a solid changes to a liquid; the solid Temperature at which a solid changes to a liquid; the solid and liquid have the same vapor pressureand liquid have the same vapor pressure

DecompositionDecomposition– Change in the chemical properties resulting from being Change in the chemical properties resulting from being

heatedheated Specific heatSpecific heat

– Amount of energy required to raise the temperature of 1g of Amount of energy required to raise the temperature of 1g of substance exactly 1substance exactly 1ooCC

– Heat = (sample mass)(specific heat)(change in temperature)Heat = (sample mass)(specific heat)(change in temperature)

HEATHEAT

Heat of fusionHeat of fusion

– Amount of energy required to melt 1g of Amount of energy required to melt 1g of solid at constant temp.solid at constant temp.

Heat of vaporizationHeat of vaporization

– Amount of energy required to evaporate Amount of energy required to evaporate 1g of liquid at constant temp.1g of liquid at constant temp.