1.(3分)条件自由度为0的点:M、N、Q、R;条件自由度为0的线:ENC、PQS 2.
de:Ф=1,f*=2-1+1=2
ef:Ф=2,f*=2-2+1=1 ff’:Ф=3,f*=2-3+1=0 f’g:Ф=2,f*=2-2+1=1 gg’:Ф=3,f*=2-3+1=0
(2分) (5分) 五、证明题(5分)
∵dH=TdS+Vdp ∴(?H?S)T?T()T?V ?p?p?V?S)T=?()p
?T?p又∵(∴(?V?H)T =?T()p?V
?T?p六、计算题(34分) 1.(16分) (1)等温可逆压缩:
ΔU=0
ΔH=0
6p?W =nRTln?=1×8.314×298.15ln6=4.44kJ?mol-1
pQ=-W=-4.44kJ?mol-1 ΔS=
QR?4440?=-14.89J?K-1 T298.15ΔA=ΔU-TΔS=-298.15×14.89=4.44kJ ΔG=ΔH-TΔS=-298.15×14.89=4.44kJ
(2)绝热可逆压缩:
Q=0
ΔS=
QR?0 T1??∵p1T1?p2T2
?1???5 / 7
∴1001?75298.15?600T2
751?7575T2=497.47K ∵ ΔU=Q+W
∴ΔU= W=nCv,m(T2-T1) =1×2.5×8.314×(497.47-298.15) =4.14kJ
ΔH=nCp,m(T2-T1) =1×3.5×8.314×(497.47-298.15) =5.79kJ
ΔA=ΔU-SΔT =4140-205.03×(497.47-298.15) =-36.73kJ
ΔG=ΔH-SΔT =5790-205.03×(497.47-298.15) =-35.08kJ 2.(18分) 298K;ΔrHkJ?mol-1M2ub6vSTnP ΔrS?m,1=
?m,1=
??BB??fHm(B,298K)=-30.585+(-393.51)-(-501.66)=77.565
??BB?Sm(298K)=121.8+213.8-167.4=168.2 J?K-1?mol-1
??ΔrG?m,1=ΔrHm,1-T1ΔrSm,1=77565-298×168.2=27.441kJ?mol-1
ΔrGm,1=-RTlnK?p,1
?lnK?p,1=?27441=-11.076
8.314?298K?104 p,1=6.46× ΔrCp=
???BBCp,m(298K)=65.7+37.6-109.6=-6.3J?mol-1?K-1
? 398K:ΔrHm,2=ΔrHm,1+ ΔrSm,2=ΔrSm,1+
???398298?rCpdT=77565+(-6.3) ×100=76.935kJ?mol-1
dT=168.2+(-6.3) ×ln
398=166.377 J?K-1?mol-1 298???398?rCpT?298 ΔrGm,2=ΔrHm,2-T2ΔrSm,2=76935-398×166.377=10.717kJ?mol-1 ΔrGm,2=-RTlnKp,2 ∴lnKp,2=?????10717=-3.239
8.314?398Kp,2=0.0392
6 / 7
7 / 7