Phases of Matter and Solutions

Phases of Matter and SolutionsMr. NylenChemistryReview of CalorimetryWorksheet Reviewing what we knowUse worksheet to help you reviewSolidsLiquidsGasesFor help look to:Review book page 45Text page 6-7 Solids, liquids, and gases are states of matterPages 424-426 Properties of gasesPage 443 Paragraph next to brown bottleComparison of phases at the molecular level (p. 1) Solids Liquids GasesComparison of Phases (p. 1-2)PropertySolidLiquidGasOrderliness

Particle Movement

Interparticle distances

Density

Interparticle forces of attractionComparison of Phases (p. 1-2)PropertySolidLiquidGasInterparticle Forces of AttractionKinetic Energy of ParticlesDiffusion RatesCompressibilityShapeVolumeAdditional Physical PropertiesSolids usually have a crystalline structuresRegular repeating geometric arrangement of atomsLiquids Exhibit unique properties such as:volatility (ability to evaporate)Viscosity (resistance to flowing)Surface tension (ability of particles to hold together)As the forces of attraction between particles in a liquid increase, the volatility decreases, the viscosity increases, and the surface tension increasesAmorphous SolidsSuper cooled liquids Liquids that appear to be solid but yet they do flow slowly over time when force is applied. They have no observable crystalline structure. Examples include some plastics, rubber, butter, and amorphous sulfur.

Viscosity of amorphous solidsThe viscosity (resistance to flow) of amorphous materials increases with decreasing temperature and decreases with increasing temperatureVegetable oil is too think to run in cars, so you have to heat it before you burn it

Phase Changes and EnergyPhase change diagramRelease energy, exothermicAbsorb energy, endothermicSolidLiquid GasHeat of FusionAmount of heat absorbed when 1g of a substance melts at its melting pointSame amount of heat as heat of crystallization

Heat of fusion = heat needed to melt a fused solidHeat of crystallization = heat needed to fuse together a liquid

1 gram

1 gram waterHeat of FusionUnits = Joules/gramFormula:

Hf equals heat of fusionLook up Hf values in reference tables BWaters is 334 J/g

Heat of VaporizationAmount of heat absorbed when 1g of a substance vaporizes at its boiling pointSame amount of heat as heat of condensation

Heat of vaporizationUnits: Joules/gramFormula

Look up heats of vaporization on table BWaters is 2260 J/gram

Heat causing temperature changeRemember that we can calculate the amount of heat needed to change the temperature of a certain mass of water

Where c is the specific heat of water (4.18)T is temperature changeMass is mass of water

TricksWhen approaching problems, figure out if the substance is fusing (melting/freezing), vaporizing (boiling/condensing), or just changing temperatureLook up the corresponding value on the reference table and use the correct formula

Practice ProblemsRB pg. 65, 30-46

Lab Heat of Fusion of IceCalorimetry

Problem Set (and Turn in Lab)Complete the following:Show phase changes, endo, and exoSolidLiquid GasReview:When approaching problems, figure out if the substance is fusing (melting/freezing), vaporizing (boiling/condensing), or just changing temperatureLook up the corresponding value on the reference table and use the correct formula

Problem Set (until 12:35)How much heat is needed to completely melt 12.45 gram of ice at 0 celcius, heat it to 100 celcius, and completely boil it?Step 1 (melt it)

Step 2 (heat it)

Step 3 (boil itHeating Curves pg. 8

Heating from solid phase at 100 J/minCalculations:Heating Curves and Energy

PEKE(Temp)ABBCCDDEHeating from solid phase at 100 J/minNotes page 10 togetherCooling Curve

PEKE(Temp)ABBCCDDENotes pg. 11Try 12-13 on your ownHW review book pg. 60#1-16Some weve already done beforeLab Heat of crystallization of WaxHW Due TuesdayPg 12 - 14 notesReview HomeworkGo over page 12-14 in notes

Notes pg. 15-16A heating curve is givenDetermine the KE and PE for each intervalRemember, if KE increases, PE stays the sameCreate your own cooling curveWe will be doing this again in the lab

Energy, and Heating Curves

Lab Cooling Curve for Lauric Acid

HomeworkFinish LabRB pg. 47, 1-16Review HomeworkGo over RB pg. 47, 1-16Go over Lauric Acid LabNotes p. 17Work through pg. 17-18

Notes p. 19-20Work in your lab groups to complete these questionsPut answers on separate sheet of paper and hand in with all group members namesReview Pg. 21-22Go over in classEquilibrium Vapor Pressure Notes p. 23Defined: Vapor pressure is pressure exerted on the surface of a liquid or solid by particles of the substance that have changed over to vapor phaseAs more particles are converted to vapor, vapor phase increases, vapor pressure increases

Relationship between vapor pressure and Boiling pointBoiling bubbles of vapor form under surface then rise to the top as liquid turns to a gasIn order to boil vapor pressure in bubble Has to be equal to the air pressure outsideIf pressure outside is greater bubble will collapse

Questions:As the pressure on the surface of a liquid decreases, the temperature at which the liquid will boil willA. IncreaseB. DecreaseC. Remain the same

The vapor pressure of a liquid is .95 atm at 600C. The normal boiling point of the substance could be200C 300C 500C 700CNotes p. 24P. 24 togetherP. 25 on your ownReview IMF complete study guide p. 27Intermolecular Forces of AttractionDipole-Dipole Attraction:Dipole = polar moleculeDipole = 2 poles, like a magnet

Hydrogen BondingVery Very Very strong dipole-dipole attractionOccurs between molecules that contain hydrogen bonded to small, highly electronegative elements (F, O, N)

Van der Waals Forces (Dispersion Forces)In all molecules electrons are constantly movingAt any given instant in time MORE could end up on one side of the molecule than the otherVan der Waals forcesThis is the ONLY force of attraction that exists between nonpolar moleculesThe more electrons, the stronger the Van der Waals forcesEx:F2, Cl2, Br2, I2gas gas liquid solid

Notes p. 27 togetherPosters!Create a poster on one of the following:Amorphous SolidsPhase Change DiagramHeat of FusionHeat of VaporizationCooling CurvesHeating Curves

Follow the Rubric for your topic, your whole group will receive the same grade.Finish notes p. 28 and 29homework