Exam

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MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.1) Ifthetemperatureofanironsphereisincreased

A) itsmasswilldecrease.B) itsvolumewilldecrease.C) itsdensitywillincrease.D) itsdensitywillremainunchanged.E) itsdensitywilldecrease.

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2) Twosteelspheresaremadeofthesamematerialandhavethesamediameter,butoneissolidandtheotherishollow.IftheirtemperatureisincreasedbythesameamountA) thesolidspherebecomesheavierandthehollowonebecomeslighter.B) thetwospheresremainofequalsize.C) thesolidspherebecomeslighterandthehollowonebecomesheavier.D) thesolidspherebecomesbiggerthanthehollowone.E) thehollowspherebecomesbiggerthanthesolidone.

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3) Achunkofice(T=20C)isaddedtoathermallyinsulatedcontainerofcoldwater(T=0C).Whathappensinthecontainer?A) Someofthewaterfreezesandthechunkoficegetslarger.B) Theicemeltsuntilthermalequilibriumisestablished.C) Thewatercoolsdownuntilthermalequilibriumisestablished.D) Noneoftheabovethingshappen.

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4) Anarchitectisinterestedinestimatingtheheatloss(inkcal/s)throughasheetofinsulatingmaterialasafunctionofthethicknessofthesheet.Assumingfixedtemperaturesonthetwofacesofthesheet,whichoneofthegraphsinthefigurebestrepresentstherateofheattransferasafunctionofthethicknessoftheinsulatingsheet?

A) A B) B C) C D) D E) E

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5) Afixedamountofidealgasisheldinarigidcontainerthatexpandsnegligiblywhenheated.At20Cthegaspressureisp.Ifweaddenoughheattoincreasethetemperaturefrom20Cto40C,thepressurewillbeA) greaterthan2p.B) impossibletodeterminesincewedonotknowthevolumeofgasinthecontainer.C) impossibletodeterminesincewedonotknowthenumberofmolesofgasinthe

container.D) equalto2p.E) lessthan2p.

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6) Whichcontainsmoremolesofmaterial:80gramsofheliumgas(He,havingatomicweight4.0g/mol)or400gramsofargongas(Ar,havingatomicweight40g/mol)?A) heliumB) argonC) Bothcontainthesamenumberofmoles.

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7) Amoleofoxygen(O2)moleculesandamoleofcarbondioxide(CO2)moleculesatthesametemperatureandpressurehaveA) differentvolumes.B) thesamenumberofmolecules.C) differentaveragekineticenergypermolecule.D) thesamenumberofatoms.E) thesameaveragemolecularspeeds.

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8) Ifwedoubletherootmeansquarespeed(thermalspeed)ofthemoleculesofagas,thenA) itstemperaturemustincreasebyafactorof 2.B) itstemperaturemustincreasebyafactorof4.C) itspressuremustincreasebyafactorof4.D) itstemperaturemustincreasebyafactorof2.E) itspressuremustincreasebyafactorof2.

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9) Anidealgasiskeptinarigidcontainer.Whenitstemperatureis100K,themeanfreepathofthegasmoleculesis.Whatwillbethemeanfreepathofthemoleculesat400K?A) /2 B) 2 C) /4 D) 4 E)

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10) Whenagasundergoesanisothermalprocess,thereisA) nochangeinthetemperatureofthegas.B) noheataddedtothegas.C) noworkdoneby(oron)thegas.D) nochangeinthepressureofthegas.E) nochangeinthevolumeofthegas.

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11) TheprocessshowninthepVdiagraminthefigureisan

A) isothermalexpansion.B) isochoricexpansion.C) isochoriccompression.D) adiabaticexpansion.E) isobaricexpansion.

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12) WhenafixedamountofidealgasgoesthroughanisothermalexpansionA) itsinternal(thermal)energydoesnotchange.B) itstemperaturemustdecrease.C) itspressuremustincrease.D) thegasdoesnowork.E) noheatentersorleavesthegas.

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13) WhenafixedamountofidealgasgoesthroughanisochoricprocessA) noheatentersorleavesthegas.B) itstemperaturemustincrease.C) itsinternal(thermal)energydoesnotchange.D) itspressuremustincrease.E) thegasdoesnowork.

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14) Whenanidealgasincreasesinvolumeatconstantpressure,theaveragekineticenergyofthegasmoleculesA) doesnotchange.B) decreases.C) mayormaynotchange,butinsufficientinformationisgiventomakesucha

determination.D) increases.E) mayeitherincreaseordecrease,dependingonwhetherornottheprocessiscarriedout

adiabatically.

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15) Isitpossibletotransferheatfromahotreservoirtoacoldreservoir?A) Yes;thiswillhappennaturally.B) Theoreticallyyes,butithasntbeenaccomplishedyet.C) No;thisisforbiddenbythesecondlawofthermodynamics.D) Yes,butworkwillhavetobedone.

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16) Isitpossibletotransferheatfromacoldreservoirtoahotreservoir?A) Yes;thiswillhappennaturally.B) No;thisisforbiddenbythesecondlawofthermodynamics.C) Theoreticallyyes,butithasntbeenaccomplishedyet.D) Yes,butworkwillhavetobedone.

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17) Anenginemanufacturermakestheclaimthattheenginetheyhavedevelopedwill,oneachcycle,take100Jofheatoutofboilingwaterat100C,domechanicalworkof80J,andexhaust20Jofheatat10C.What,ifanything,iswrongwiththisclaim?A) Anenginewouldoperatebytakinginheatatthelowertemperatureandexhaustingheat

atthehighertemperature.B) Thereisnothingwrongwiththisclaimbecause100J=20J+80J.C) TheefficiencyofthisengineisgreaterthantheidealCarnotcycleefficiency.D) Theheatexhaustedmustalwaysbegreaterthantheworkdoneaccordingtothesecond

lawofthermodynamics.E) Thisengineviolatesthefirstlawofthermodynamicsbecause100J+20J80J.

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18) ThesecondlawofthermodynamicsleadsustoconcludethatA) disorderintheuniverseisincreasingwiththepassageoftime.B) thetotalenergyoftheuniverseisconstant.C) thetotalenergyintheuniverseisdecreasingwithtime.D) thetotalenergyintheuniverseisincreasingwithtime.E) itistheoreticallyimpossibletoconvertworkintoheatwith100%efficiency.

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19) Asaresultofanynaturalprocess,thetotalentropyofanysystemplusthatofitsenvironmentA) alwaysstaysthesame. B) sometimesdecreases.C) neverdecreases. D) neverincreases.

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20) Anicecubeat0Cisplacedinaverylargebathtubfilledwithwaterat30Candallowedtomelt,causingnoappreciablechangeinthetemperatureofthebathwater.Whichoneofthefollowingstatementsistrue?A) Thenetentropychangeofthesystem(icepluswater)iszerobecausenoheatwasadded

tothesystem.B) Theentropygainedbytheicecubeisequaltotheentropylostbythewater.C) Theentropyofthewaterdoesnotchangebecauseitstemperaturedidnotchange.D) Theentropyofthesystem(icepluswater)increasesbecausetheprocessisirreversible.E) Theentropylostbytheicecubeisequaltotheentropygainedbythewater.

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AnswerKeyTestname:CONCEPTUALMCQCHP17TO20

1) E2) B3) A4) C5) E6) A7) B8) B9) E10) A11) E12) A13) E14) D15) A16) D17) C18) A19) C20) D

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