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2jnpTidefinGG,G=GAnA+GBnB34ikinpTinTnpdnnXdppXdTTXdXjkk 1,jnpTidefinXX,jnpTidefinVV,-偏摩尔量偏摩尔量-偏摩尔体积偏摩尔体积 jnpTidefinGG,-偏摩尔吉布斯自由能偏摩尔吉布斯自由能5ikinpTinTnpdnnXdppXdTTXdXjkk 1,ikiidnXdX 1ikiidnGdG 1()T,pikiinTnpdnXdppXdTTXdXkk 1,ikiidnVdV 16slopenVVjnpTii ,V ni7BnBAnAVdnVdnVdVBA 0008V=VAnA+VBnB若系统有个若系统有个k组分:组分:ikiinXX 1ikiinGG 1BnBAnAVdnVdnVdVBA 000X=XAnA+XBnB-集合公式集合公式 由于制备过程中保持浓度不变,故偏摩尔体积不变:由于制备过程中保持浓度不变,故偏摩尔体积不变:9jnpTidefinXX,10jnpTiiinGG,11jnpTiiinGG,ikinpTinTnpdnnGdppGdTTGdGjkk 1,ikiidnVdpSdTdG 1 ikiipTdndG 1,)(12ikiidnVdpSdTdG 1 ikiipTdndG 1,)(rWVdpSdT rW 13iidnVdpSdTdG iidnpdVSdTdA iidnVdpTdSdH iidnpdVTdSdU jjjjnVSinpSinVTinpTiinUnHnAnG,14ipiST iTiVp 2)/(THTTipi pnpTipijnGTT ,jnpTpiTGn,inpTiSnSj ,15ikiipTdndG 1,)(161718 ddnii 192021 ppmTmdpVG)(ppRTpGpGmmln)()(ppRTTln)(22 ppRTTiiiln)(23 BAppBppAmixdpVdpVG BBAAmixxnxnRTGlnln ppnppnRTBBAAlnln BAppBppApdpnpdpnRT24 ppRTTnppRTTnBBBAAAln)(ln)(ppnppnRTGBBAAmixlnln ppRTTnppRTTnBBAAln)(ln)(BBAAxnxnRTlnln 25 pfRTTppRTTln)(ln)(令逸度令逸度 f=p26f 0p p27 CdefrTTT Cdefrppp prTr=1.5Tr=1.3(对比压力)(对比压力)(对比温度)(对比温度)Tr=1.0 2829dppRTfRTd ln)/ln()(pfRTT 30dppRTfdRTppff lnlnln*)(lnlnppppRTffRT RTppf lnRTppef/RTppppff*)(lnln 31)/ln()(pfRTT ppRTVm)1(32接上页接上页dpppfdppff 11lnlnlnppppff 11lnlnlndpppRT 11积分积分)1(lnppRTdpfRTd )1(ppf )1(*)1(lnpppp )1(ppf 33mmVBRTpV 2mmVBVRTp 34p1=p1*x1 p2=Kh,x x2 35p1 x1p1*p1=p1*x1 0 x1 1p1*p1=p1*p1 =p1*(1 x1)=p1*x2 适用条件:适用条件:稀稀溶液溶液(x1 1)36p2 x2p2=Kh,xx2=Kh,m m=Kh,c c 适用条件:适用条件:1、稀稀溶液溶液(x2 0)(挥发性(挥发性溶质或气体)溶质或气体)2、气、液中分子状态相同气、液中分子状态相同 0 x2 1Kh,xp2022,2 xxhxpK3738p B 01p B xBKh,x pB*Kh,xpB*39pA*0 xB 11 xA 0pB*p4041BBAAAAAAxpxpxpppy*200.0)1(97.296.996.9 AAAxxx42p2 0 x2 1p2*Kh,x 43p2 0 x2 1Kh,xp2*Kh,x 44)/()/(/BBAABBBMwMwMwx 012.0)46/000.3()18/00.97(46/000.3 454647)()(llAA )()(pGpGmm 0 pVdpVmppm)(lA )(lA ppRTggAAA ln)()()()(*glAA 48)()(gslnAA )/ln()()(ppRTggAAA AAAxRTppRTgln)/ln()(*AAAxRTlnslnsln)()(BBBxRTslnslnln)()()(ln)()(lppRTglnsiiii 49 ppRTgg222ln)()()(2lns pxKRTgxh2,2ln)()/ln()(,2 pmKRTgmh )/ln()(,2 pKRTgxh 2lnxRT)/ln(mmRT )/ln()(,2 pcKRTgch )/ln(ccRT 50ln)()(22RTglnsln)()(22RTglnsln)()(22RTglnsln)()(22RTlnslns2x)/(mm)/(cc)/(,pKxh)/(,pmKmh)/(,pcKchln)()(22RTlnslnsln)()(22RTlnslns510 x2 1p2*mm p252 ppRTgsln222ln)()(222ln)()(xRTslnsln )/ln()()(22 mmRTslnsln )/ln()()(22 ccRTslnsln 222ln)()(xRTlsln 53545556凝固点:溶剂凝固点:溶剂(l)溶剂溶剂(s)平衡温度:平衡温度:Tf*溶液溶液(sln)溶剂溶剂(s)Tf 相平衡条件:溶剂化学势相等相平衡条件:溶剂化学势相等 1(sln)=1*(s)mfusG RTGRTGxmfusmfus)/(ln1 =1(s)1(l)+RT ln x1=1(s)RT ln x1=1(l)1(s)57pmfuspTTGRTx )/(1ln1 ffmfusTTRHx11ln1 若若 fusHm为常数为常数,积分积分(适用于理想溶液和稀溶液,精确求(适用于理想溶液和稀溶液,精确求Tf)2RTHmfusHG ffTTmfusxTdTRHx*1211ln 58ffffffTTTTTT 11ffmfusTRTHx 22 mKmHMRTTfmfusff 1212212nnnnn 2 ffTT11112mMMnMn 59mKTff 122/WMWm 212MWWKTff ffTWWKM 12260 bbmvapTTRHx11ln1 mKmHMRTTbmvapbb 126162 RTVxm 1,1lndpVxRTppm 1,1ln)(1,ppVm 1,mV6311,ln xRTVm RTVnnm 1,12 RTVMWcRT22 2x 12nn cRTRTVn 1264 65pApBA xB BpApBA xB B66pApBxB pApBxB pB*70(1)p1=p1*a1 ffmfusTTRHa11ln)2(1 bbmvapTTRHa11ln)3(1 RTVam 1,1ln)4(7172 ffmfusTTRHa11ln1 1543.0258127316025 RPaaVRTm7511,1012.2108.11543.0298314.8ln 74jnpTiidefinGG,75标准态标准态:p 理气理气76 ffmfusTTRHa11ln1 bbmvapTTRHa11ln1 RTVam 1,1lnp1=p1 a1 p1=p1 x2 Tf=Kf mTb=Kb m =cRT777879805 在恒温抽空的玻璃罩中封入两杯液面相同在恒温抽空的玻璃罩中封入两杯液面相同的糖水的糖水(A)和纯水和纯水(B)。经历若干小时后,两。经历若干小时后,两杯液面的高度将是(杯液面的高度将是()(A)A杯高于杯高于B杯杯 (B)A杯等于杯等于B杯杯(C)A杯低于杯低于B杯杯 (D)视温度而定。视温度而定。8182838485SdTTGTGTT 21)()(12SdTKGKG 263273)273()263(86 21)()(12ppVdppGpG8788例例4 在在300K时,液态时,液态A和液态和液态B的蒸气压分别为的蒸气压分别为 pA*=37.33kPa,pB*=22.66 kPa,当,当2mol A 和和 2mol B混合,混合,p总总=50.66 kPa,蒸气相中,蒸气相中A的物质的量分的物质的量分数数yA(g)=0.60,设蒸气为理想气体,设蒸气为理想气体求溶液中求溶液中A、B的活度和活度系数的活度和活度系数求求 mixG若溶液为理想溶液,若溶液为理想溶液,mixG89解:解:非理想溶液蒸气压与浓度的关系:非理想溶液蒸气压与浓度的关系:pi=pi*ai aA=p yA/pA*=0.814 aB=p y B/pB*=0.894 A=aA/xA=1.63 B=aB/xB=1.79 mixG=G G*=ni i ni i*=2RT(ln aA+ln aB)=1585 J mixG=G G*=ni i ni i*=2RT(ln xA+ln xB)=6915 J 909192939495969798PadxdpKBBxBxhB676230069.06.466lim0,99
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