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1、南昌大学2014上半年材料热力学重点题————————————————————————————————作者：————————————————————————————————日期：solution:Solution：,exothermicreactionForthereaction:Solution:(a)Whentheequilibriumisreached,T=500°C=773K(a)atT=300°C=573K,AlthoughtheequilibriumPO2isverylow,kineticallythereactionisnotfavouredandreactionspe
2、edisveryslow.So300°CisnotsuitableatAtT=800°C=1073K,lnPO2=-22.2,PO2=2.28´10-10atm.At800°C,iftheequilibriumisreached,nitrogencanbeofhighpuritylevel.However,atthishightemperature,particlesofCuwillweldtogethertoreduceeffectiveworksurface.Soitisnotsuitabletousethishightemperatureinpurificationeither
3、.(c)Theequilibriumoxygenpressureremainsthesamewhenthetotalpressureincreases,whichmeansahigherpuritylevelofN2.Solution:N2=2N,H2=2H，ForN2dissolving:ForH2dissolving：（a）FordissolvingN2,PN2=1atm,[N]=35cm3/100gmelt,similarly:[H]’=24.75cm3/100gmelttotalgas:[H]¢＋[N]¢=49.5cm3/100gmelt(b)[H]¢=24.75cm3/10
4、0gmelt(c)[H]¢＋[N]¢=[N](0.33)1/2/1+[H](0.33)1/2/1=20.10+20.10=40.2cm3/100gmeltSolution：（1）0.2（2）（3）Solution:(a)(b)(c)Solution:(b)(c)答案更正为：TemperaturePhaseCompositionFraction1300Liquid6061.5α838.5β9901000+Liquid7050.8α949.2β9801000-Liquid_0α763.7β9836.3Solution:SolutionSolution：SolutionSolution:s
5、olution:Solution:Solution:(a)At0°C,DG=0,TmDS=DH(b)At0°C,DG=0©areversibleprocesscanbedesignedasfollowstodothecalculation:Ice,0°Cwater,0°Cwater,-5°Cice,-5°C（1）（2）（3）（4）（d）Solution:(a)(b)No,diamondisnotthermodynamicallystablerelativetographiteat298K.(c)(c)AssumingNatm,DG=0,reversibleprocessesasfo
6、llowingcanbedesignedtorealizethis,graphite,298K,1atm（1）（4）（2）graphite,298K,Natmdiamond,298K,Natmdiamond,298K,1atm(3)Solution:(a)Ag2O=1/2O2+2AgwhenAg2Obeginstodecompose,(a)inpureoxygenat1atm,RTlnPO2=030514-66.044T=0T=462K(b)inairatPtotal==1atm,PO2=0.21ie.30514-66.044T+RTln0.21=0T=386KSolution:(a
7、)Plot.AtT=1000K,lnKa=8.01,Ka=3010(b)SotheatmospherewilloxidizeNi.Solution:Solution:(1)(2)(3)(4)(5)c.d.e.Solution:The standard Gibbs free energy change for reaction I: a.b.c.; Ni is stable under this condition, and NiO is not stabl
