ap chemistry spring 2020 mr. cameron€¦ · reaction o =n p Δg f ∑o(products)−n r Δg f...
TRANSCRIPT
![Page 1: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/1.jpg)
APChemistrySpring2020Mr.Cameron
![Page 2: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/2.jpg)
1stLawofThermodynamics
![Page 3: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/3.jpg)
Spontaneous?
• Considerthefollowingphysicalandchemicalprocesses– Awaterfallrunsdownhill,butneveruphill,spontaneously
– Alumpofsugarspontaneouslydissolvesinacupofcoffee,butsugardoesnotspontaneouslyreappearinitsoriginalform
– Waterfreezesspontaneouslybelow0˚C,andicemeltsspontaneouslyabove0˚C(at1atm).
![Page 4: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/4.jpg)
Spontaneous?
• Considerthefollowingphysicalandchemicalprocesses– HeatflowsfromahoIerobjecttoacolderone,butthereverseneverhappensspontaneously.
– Theexpansionofagasinanevacuatedbulbisaspontaneousprocess.Thegatheringofallthemoleculesintoonebulbisnotspontaneous.
![Page 5: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/5.jpg)
Spontaneous?
• Considerthefollowingphysicalandchemicalprocesses– Apieceofsodiummetalreactsviolentlywithwatertoformsodiumhydroxideandhydrogengas.However,hydrogengasdoesnotreactwithsodiumhydroxidetoforwaterandsodium.
– Ironexposedtowaterandoxygenformsrust,butrustdoesnotspontaneouslychangebacktoiron.
![Page 6: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/6.jpg)
Spontaneous
• AreacNonthatdoesoccurunderthegivensetofcondiNonsiscalledspontaneous.
• ProcessesthatoccurspontaneouslyinonedirecNoncannot,underthesamecondi:on,alsotakeplacespontaneouslyintheoppositedirecNon.
• Spontaneousdoesnotmeanfast.Itdoesmeanthatitiscertaintooccur.
![Page 7: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/7.jpg)
Entropy-S
• Adirectmeasureofrandomnessordisorderofasystem.
• Adrivingforceforaspontaneousprocessisanincreaseintheentropyoftheuniverse.
![Page 8: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/8.jpg)
Entropy-S
• Entropyiscloselyrelatedtoprobability• ThemorewaysaparNcularstatecanbeachieved,thegreateristhelikelihoodoffindingthatstate.
• NaturespontaneouslyproceedstowardthestatesthathavethehighestprobabiliNesofexisNng.
![Page 9: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/9.jpg)
![Page 10: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/10.jpg)
PosiNonalEntropy
![Page 11: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/11.jpg)
Processesthatleadtoanincreaseinentropy(ΔS>0)
![Page 12: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/12.jpg)
2ndLawofThermodynamics
• Inanyspontaneousprocessthereisalwaysanincreaseintheentropyoftheuniverse.
• Theentropyoftheuniverseincreasesinaspontaneousprocessandremainsunchangedinanequilibriumprocess.
ASpontaneousProcess:ΔSuniv = ΔSsys +ΔSsurr >0AEquilibriumProcess:ΔSuniv = ΔSsys +ΔSsurr =0
![Page 13: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/13.jpg)
EffectsofTemperature
• LookingatΔSsysandΔSsurr,consider:
• WhatisthesignofΔSsys
• WhatisthesignofΔSsurr
H2O(l)⎯→⎯ H2O(g)
![Page 14: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/14.jpg)
EffectsofTemperature-CharacterisNcs
• SignofΔSsurr:dependsonthedirecNonoftheflowofheat– Exothermicprocessesincreasetheentropyofthesurroundings
– Endothermicprocessesdecreasetheentropyofthesurroundings
![Page 15: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/15.jpg)
EffectsofTemperature-CharacterisNcs
• MagnitudeofΔSsurr:dependsonthetemperature
• “Howmuchwillthetransferofheataffectthesurroundings?”– DependsdirectlyonthequanNtyofheattransferred
– Dependsinverselyonthetemperature
![Page 16: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/16.jpg)
CalculaNngΔSsurr
• Constanttemperature:K• Constantpressure• NegaNvesignbecauseΔHisdeterminedwithrespecttothesystem.
ΔSsurr = −
ΔHT
![Page 17: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/17.jpg)
PracNceCalculaNngΔSsurr
InthemetallurgyofanNmony,thepuremetalisrecoveredviadifferentreacNons,dependingonthecomposiNonoftheore.Forexample,ironisusedtorecoveranNmonyinsulfideoresandcarbonisusedforoxideores.CalculateΔSsurrforeachofthesereacNonsat25˚Cand1atm.
Sb2S3(s)+3Fe(s)⎯→⎯ 2Sb(s)+3FeS(s)ΔH = −125kJSb4O6(s)+6C(s)⎯→⎯ 4Sb(s)+6CO(g)ΔH =778kJ
![Page 18: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/18.jpg)
GibbsFreeEnergy(FreeEnergy)
• IfΔG>0–NotSpontaneous
• IfΔG=0–SystematEquilibrium
• IfΔG<0–SpontaneousJosiahWillardGibb
ΔG = ΔH −TΔS
![Page 19: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/19.jpg)
FreeEnergy–Spontaneous?Case SignofΔHsys SignofΔSsys SignofΔG Spontaneous?1 - +2 + -3 - -4 + +
![Page 20: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/20.jpg)
3rdLawofThermodynamicsTheentropyofapurecrystallinesubstanceatabsolute
zeroisS=0at0K.
![Page 21: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/21.jpg)
CalculaNngΔHo,ΔSoandΔGo
ΔHreactiono = npΔHf
o(products)−∑ nrΔHfo(reactants)∑
ΔSreactiono = npΔS
o(products)−∑ nrΔSo(reactants)∑
ΔGo = ΔHo −TΔSo
![Page 22: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/22.jpg)
PracNceCalculaNngΔHo,ΔSoandΔGo
ConsiderthereacNon
carriedoutat25˚Cand1atm.CalculateΔHo,ΔSo,andΔGo.
2SO2(g)+O2(g)⎯→⎯ 2SO3(g)
![Page 23: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/23.jpg)
CoupleofThoughtsonΔGo
• StateFuncNon–CanuseHess’sLaw• CanuseΔGo
f:
ΔGreactiono = npΔGf
o(products)−∑ nrΔGfo(reactants)∑
![Page 24: AP Chemistry Spring 2020 Mr. Cameron€¦ · reaction o =n p ΔG f ∑o(products)−n r ΔG f ∑o(reactants) AP Chemistry Spring 2020 Mr. Cameron Title: Chapter 16.pptx Author: Kevin](https://reader034.vdocument.in/reader034/viewer/2022042404/5f19871b6f9db119f7625819/html5/thumbnails/24.jpg)
APChemistrySpring2020Mr.Cameron