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得到K?P=17.39-
51034
4.575T??(1) 计算在573K时,反应的ΔrG?mΔrHm和ΔrSm
(2)始时用等量I2和环戊烯混合,温度为573K,起始总压为101.325Kpa,试求平衡后I2分压。
(3)若起始压力为1013.25Kpa,试求平衡后I2的分压。 解:(1)
51034InK?p=17.39-
4.575T51034T=573K时 InK?p=17.39-
4.575?573015In K?p=-2.073 K?p=0.125
?ΔrG?m=-RT InKp=-8.314×573×(-2.073)=9.88KJ
??rHm1??C RTInK?p=
?51034?rHm 解得:ΔrH??m=92.74KJ R40575??ΔrG?m=ΔrHm—TΔrSm(恒温)
9.88=92.74-573ΔrS?m
?1解得:ΔrS? m=144.6J?K2)I2 + 环戊烯 = 2HI + 环戊二烯 开始P0 P0 0 0 平衡P0-X P0-X 2X X P0=
P总101.35??50.66KPa 2222?PHI??P环戊二烯??2x??x?????????????x3101.325101.325?P??P???????225.33?(50.66?x)2?PI2?50.66?x??????Kp= ???P??101.325???x3即0.125?解得x?15.72kPa225.33?(50.66?x)
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14.CO2与H2S在高温下有如下反应
CO2(g)?H2S(g)?COS(s)?H2O(g)
今在610K时,将4.4×10-3Kg的CO2加入2.5dm3体积的空瓶中然后再充入H2S使总压为1013.25Kpa。平衡后水的摩尔分数为0.02。同上实验,再620K,平衡后水的摩尔分数为0.03。(计算时可假定气体为理想气体)
? (1)计算610K时的KP。 ? (2)求610K时的?rGm。
? (3)计算反应的热效应?rHm。
解:(1)nCO24.4?10?3kg??0.1mol 44?10?3kg/mol开始时pV?nRT
PCO2?nRT0.1?8.314?610??202.86kPa ?3V2.5?10 CO2(g)?H2S(g)?COS(g)?H2O(g) 开始 202.86kPa 810.39kPa 0 0
平衡 202.86-p 810.39-p p p 平衡后:xH2O?pH2Op总?pH2O1013.25?0.02
解得:pH2O(g)?20.27kPa
pCOSpH2O???20.27?20.27?PP?KP??2.849?10?3 pCO2pH2S(202.86?20.27)?(810.39?20.27)??P?P??3(2) ?rGm??RTlnK?p??8.314?610?ln(2.849?10)?29.73kJ
(3)620K时平衡后 xHO?pH2Op总?pH2O1013.25?0.03
解得:pH2O(g)?30.40kPa
pCO2?202.86?30.40?172046kPa 则平衡后:pH2O?810.39?30.40?779.99kPa
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pCOSpH2O????PP?30.40?30.40?6.870?10?3 KP?pCO2pH2S172.46?779.99??P?P ln?KP2?KP1??rHm11???(?)
RT2T1??rHm6.870?10?311ln???(?)
8.3146206102.849?10?3??276.7kJ 解得:?rHm
15.(1)在1120℃下用H2(g)还原FeO(s),平衡时混合气体中H2(g)的摩尔分数为0.54。求FeO(s)的分解压。已知同温度下,
2H2O(g)?2H2(g)?O2(g)K??3.4?10?13;(2)在炼铁炉中,氧化铁按如下反应
还原: FeO(s)?CO(g)?Fe(s)?CO2(g) 求:1120℃下,还原1molFeO需要CO若干摩尔? 已知同温度下2CO2(g)?2CO(g)?O2(g) K??1.4?10?12 解:(1)FeO(s)?H2(g)?Fe(s)?H2O(g) ① 平衡气体中xH2?0.54,xH2O?1?0.54?0.46
???0 Kp,1?Kx??xH2OxH2?0.46?0.852 0.542H2O(g)?2H2(g)?O2(g) ②
?13 K?p,2?3.4?102FeO(S)?2Fe(s)?O2(g) ③
①×2+②=③
??2?13?13K??K?K?0.852?3.4?10?2.47?10 p,3p,1p,2??2Kp,3??pO2p? pO2?Kp,3p?2.47?10???13?101.325?2.5?10?11KPa
(2)2CO2(g)?2CO(g)?O2(g) ④
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FeO(s)?CO(g)?Fe(s)?CO2(g) ⑤
?KP,3?K??p,5?K??p,4??2.47?10?????1.4?10?12???12?13????0.42 ?12(③-④)÷2=⑤
设1120℃下,还原1molFeO需要nmolCO
2FeO(s)?CO(g)?Fe(s)?CO2(g)
1mol n 0
n-1 1mol ?V?0
1?0.42 n?1解得:n?3.38molk?p,5?kn?16.已知298.15K,CO(g)和CH3OH(g)标准摩尔生成焓?fH?m分别为-110.52
及-200.7KJ.mol?1.K?1, CO(g).H2(g).CH3OH(I)的标准摩尔熵S?m分别为197.67,130.68及127J.mol?k?1.又知298.15K甲醇的饱和蒸气压为-16.59Kpa
?摩尔汽化热?vapHm?38.0KJ.mol?1,蒸气可是为理想气体。
?利用上述数据,求298.05K时,反应CO(g)+2 H2(g)= CH3OH(g)的?rGm?及KP。
解: 101.325KPa CO(g)+2 H2(g)?CH3OH(g) ??S1
101.325Kpa CH3OH(I) ? ??S2
?S3 ??S4
16.59Kpa CH3OH(I)? CH3OH(g)
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????S1?Sm,CH3OH(g)?2Sm,H2(g)?Sm,co(g)
=127-2?130.68-197.67=-332.03J.mol?1 ?S2?0 ?S1??S4?nRTln?Hm,vapT38?103??127.45J.mol?1 298.15p116.25?1?8.314?ln??15.04J.mol?1 p2101.35?rSm??S1??S2??S3??S4??219.62J.mol?1
????rHm??fHm,CH3OH(g)?2?fHm,H2(g)??fHm,CO(g)
=-200.7-(-110.52)=-90.18KJ.mol?1
????rGm??rHm?Tg?rSm??90.18?298.15?(?219.62)?103
=-24.73KJ.mol?1
???rGm=---RTlnKP
3?即—24.73?10??8.314?298.15?lnKP
?4 KP=2.15?10
17
求25℃时,下术反应的反应
?ka
CH3COOH(I)+C2H5OH(I)=CH3COOC2H5(I)+H2O(I)已知个物质 的标准生成
?自由能?fGm
? 物质 ?fGm(kJ.mol?1)
CH3COOH(I) —395.8 CH3COOC2H5(I) —341.1
H2O(I) —236.6
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