一、 1 mol 理想气体由1013.25 kPa ,5 dm3, 609.4 K反抗恒外压101.325 kPa膨胀至 40 dm3,压力等于外压,求此过程的 W、Q、△U、△H、△S、△A、△G。已知 CV,m=12.5 J ·mol-1· K-1;始态熵值S1=200 J ·K-1。解:KKTVpVpT5.4874.6095401011112223332111,2111,21101.325 104053.546 103.546112.5487.5609.41.524112.5 8.314487.5 609.42.5371.5243.5462.022ambV mp mWpVVPamJkJUnCTTmolJ molKKkJHnCTTmolJ molKKkJQUWkJkJkJ1111122,111121487.51112.58.314ln8.314ln14.67609.41014.67200214.67p mTpSnClnnRlnmolJ molKJ molKJ KTpSSSJ KJ K322112.537 10487.5 214.5609.420014.77GHT ST SJkJ二、始态为T1=300 K,p1=200 kPa 的某双原子理想气体1 mol,经先绝热可逆膨胀使压力降到100 kPa,再恒压加热到T2=300 K ,p2=100 kPa 的终态,求整个过程的Q,△ U,△H,△S,△G。解:JKJKSTHGKJmolRlnppnRlnSHU1729762.53000762.51210;01121JKRmolTTnCHQQKKTppTmp15681.2463002711.246300223,224.14.1111212四、甲醇( CH3OH)在 101.325 kPa 下的沸点 (正常沸点) 为 64.65 ℃,在此条件下的摩尔蒸发焓ΔvapHm=35.32kJ · mol-1 。求在上述温度压力条件下,1 kg 液态甲醇全部成为甲醇蒸气时的Q、W、Δ U、Δ H,Δ S 及Δ G。视甲醇蒸气为理想气体。解:根据题意可知,此蒸发过程是在相变温度及其平衡压力下进行的可逆相变化过程,若视甲醇蒸气为理想气体,且忽略液态甲醇的体积,则有kJkJHMmHnHQmvapmvapp30.1102)32.35321000(kJJRTgnlVgVpW65.87)]15.27365.64(3145.8321000[)()]()([kJkJWQU65.1014)65.8730.1102(1263.3)15.27365.64/(30.1102/KkJKkJTQSr0G等温恒外压δQr=0 1mol 理想气 体T1=300K p1 = 200 kPa 1mol 理想气 体T2 = P2 = 100 kPa 1mol 理想气体T3=300K P3 = 200 kPa 三、 1 mol ,25 ℃、 p?的过冷水蒸气在p?下变为同温同压下的水,求过程的W,Δ U,Δ H,Δ S,Δ G。已知 25 ℃时水的饱和蒸汽压力为3167 Pa ;25 ℃时水的凝聚焓1mH43.83kJ mol。解:kJHHHkJmolkJmolHnHHVap83.43;083.4383.431;0211相变相变121lnppnRTG0相G(水的可逆相变过程)02G ( 纯凝聚相物质的G随压力变化很小) 21GGGG相J855800ln12ppnRT118.17515.298855843830KJKJTGHS1298.152479glgWp Vp VVpVnRTmolRKJ43830 247941351gUHpVHpVHnRTJJ...