?p1106???1?8.314ln5?J·K?1?19.14J·K?1 (5分) ?S?nRlnp210??G ?A????T?S?(?300?19.14)J?? (8分)
12、已知各物质在298.15K时的热力学函数数据如下: 物质 C2H5OH(g) C2H4(g) H2O(g) ??fHm ? 235.30 52.283 ?241.80 KJ.mol-1S?m282.0 219.45 188.74 J.mol-1.K-1 CP,m65.44 43.56 33.577 J.K?1.mol?1 对下列反应: C2H5OH(g) = C2H4(g) + H2O(g) 求此反应在398K时,标准压力下ξ=1mol时的Q,W,?U,?H,?S及?G 12、解:⑴??1mol
?H????rHm??rHm
?rCp,m=?43.56?33.577?65.44??11.70J?mol?1?k?1
??rHm?298???52.283?241.8?235.3?KJ?45.783KJ
Q?398p?398???rH?m?398???rHm?298???298?Cp,mdT
?45.783?11.70?(398?298)?10?3?46.953KJ??1rSm?298??219.45?188.74?282?126.19J?mol?1?k?
??398rS?m?398???rSm?298???298?Cp,m/TdT?126.19?11.70ln398?1?1 298?129.58J?mol?k?U??398?????????rmrHm?398??νB?g?B??RT
=46.953?1?8.314?398?10?3?43.64KJW=??rUm?398??Q?398???43.64?46.95?KJ??3.31KJ
5
????rGm?398???rHm?398??T?rSm?398???46.95?398?129.58?10?3?KJ??4.62KJ此温度范围内反应的?rH。设反应的?C?p,m?0。 13、解:ln [K(T2) / K
13、某反应在327℃与347℃时的标准平衡常数K1与K2分别为1×10-12和5×10-12。计算在
(T1)]= - ?rH/ R·???11???? TT1??2?15?10?121??1?1? 即 ln - ?H/ ( 8.314) ×?J?K?molr??
6206001?10?12?? 则?rH
= 248.88kJ ·mol-1
14、等体积的0.01mol·dm -3 的KI(aq)和0.05 mol·dm -3的AgNO3(aq)混合所得AgI溶胶,写出其胶团结构式,并注明胶核、胶粒、胶团、紧密层及扩散层,说明电泳方向。 14、解:
???AgInAg?(n?x)NO ??xNO3 m????3x?
胶核
胶粒
紧密层 扩散层
胶团
15、已知NH3(g),NO(g),及H2O(g)25 ℃的标准摩尔生成热分别为
-46?191 kJ·mol-1;90?374 kJ·mol-1;-241?835 kJ·mol-1。求25 ℃时2 mol NH3(g)氧化成NO(g)及H2O(g)反应的标准反应热?rH,?rU。 15, 2NH3(g) + 5/2O2(g) = 2NO(g) + 3H2O(g) ?rH ?rU
= ?rH
=2×90.374+3×(-241.835)-2×(-46.191)=-452.38 kJ
- ??(B,g)RT=-452.38-0.5×8.314×298.15×10-3=-453.62 kJ
B 6

