第1章 化学反应中的质量关系和能量关系 习题参考答案
1.解:1.00吨氨气可制取2.47吨硝酸。 2.解:氯气质量为2.9×103g。 3.解:一瓶氧气可用天数
n1(p?p1)V1(13.2?103-1.01?103)kPa?32L???9.6d n2p2V2101.325kPa?400L ? d-14.解:T?pVMpV ?nRmR = 318 K ?44.9℃ 5.解:根据道尔顿分压定律
pi?p(N2) = 7.6?104 Pa p(O2) = 2.0?104 Pa p(Ar) =1?103 Pa
nip n6.解:(1)n(CO2)? 0.114mol; p(CO2)? 2.87 ? 104 Pa
(2)p(N2)?p?p(O2)?p(CO2)?3.79?104Pa (3)
n(O2)p(CO2)2.67?104Pa???0.286 np9.33?104Pa7.解:(1)p(H2) =95.43 kPa (2)m(H2) =
pVM = 0.194 g RT8.解:(1)? = 5.0 mol
(2)? = 2.5 mol
结论: 反应进度(?)的值与选用反应式中的哪个物质的量的变化来进行计算无关,但与反应式的写法有关。
9.解:?U = Qp ? p?V = 0.771 kJ 10.解: (1)V1 = 38.3?10-3 m3= 38.3L
(2) T2 =
pV2= 320 K nR(3)?W = ? (?p?V) = ?502 J (4) ?U = Q + W = -758 J
(5) ?H = Qp = -1260 J
11.解:NH3(g) +
5O(g) ???3??298.15K??NO(g) + H2O(g) ?rHm= ? 226.2 kJ·mol1 2标准态4212.解:?rHm= Qp = ?89.5 kJ ?rUm= ?rHm? ?nRT
= ?96.9 kJ
13.解:(1)C (s) + O2 (g) → CO2 (g)
?? ?rHm = ?fHm(CO2, g) = ?393.509 kJ·mol?1
1CO(g) + 1C(s) → CO(g)
2
22? = 86.229 kJ·mol?1 ?rHm CO(g) +
?1FeO(s) → 2Fe(s) + CO(g)
23233 ?rHm = ?8.3 kJ·mol?1
??各反应?rHm之和?rHm= ?315.6 kJ·mol?1。
(2)总反应方程式为
3C(s) + O(g) + 1FeO(s) → 3CO(g) + 2Fe(s)
2232
2323? = ?315.5 kJ·mol?1 ?rHm由上看出:(1)与(2)计算结果基本相等。所以可得出如下结论:反应的热效应只与反应的始、终态有关,而与反应的途径无关。
???14.解:?rHm(3)=?rHm(2)×3-?rHm(1)×2=?1266.47 kJ·mol?1
???15.解:(1)Qp =?rHm== 4?fHm(Al2O3, s) -3?fHm(Fe3O4, s) =?3347.6 kJ·mol?1
(2)Q = ?4141 kJ·mol?1
???16.解:(1)?rHm =151.1 kJ·mol?1 (2)?rHm = ?905.47 kJ·mol?1(3)?rHm =?71.7
kJ·mol?1
?????17.解:?rHm=2?fHm(AgCl, s)+?fHm(H2O, l)??fHm(Ag2O, s)?2?fHm(HCl, g) ? ?fHm(AgCl, s) = ?127.3 kJ·mol?1
18.解:CH4(g) + 2O2(g) → CO2(g) + 2H2O(l)
???? ?rHm = ?fHm(CO2, g) + 2?fHm(H2O, l) ??fHm(CH4, g)
= ?890.36 kJ·mo ?1
Qp = ?3.69?104kJ
第2章 化学反应的方向、速率和限度 习题参考答案
???1.解:?rHm = ?3347.6 kJ·mol?1;?rSm = ?216.64 J·mol?1·K?1;?rGm = ?3283.0
kJ·mol?1 < 0
该反应在298.15K及标准态下可自发向右进行。
?2.解: ?rGm = 113.4 kJ·mol?1 > 0
该反应在常温(298.15 K)、标准态下不能自发进行。
??? (2)?rHm = 146.0 kJ·mol?1;?rSm = 110.45 J·mol?1·K?1;?rGm = 68.7 kJ·mol?1 >
0
该反应在700 K、标准态下不能自发进行。
???3.解:?rHm = ?70.81 kJ·mol?1 ;?rSm = ?43.2 J·mol?1·K?1;?rGm = ?43.9 kJ·mol?1
(2)由以上计算可知:
?? ?rHm(298.15 K) = ?70.81 kJ·mol?1;?rSm(298.15 K) = ?43.2 J·mol?1·K?1 ??? ?rGm = ?rHm ? T ·?rSm ≤ 0
T ≥
??rHm(298.15 K)??rSm(298.15 K) = 1639 K
33p (CO) ? p (H2) ?c (CO) ? c (H2) ?4.解:(1)Kc = Kp = p (CH4) p (H2O)c (CH4) c (H2O) K?
?p (CO) / p?? p (H) / p ? =
?p (CH)/p?? p (HO) / p???32??42 (2)Kc =
?c (N2)?? c (H2) ?c (NH3) 12 32 Kp =
2)/??p (N2)?? p (H2) ?p (NH3) 12 32
K? =
?p (N2)/1?2p ?? p (Hp ??32p (NH3) /p
(3)Kc =c (CO2) Kp =p (CO2) K? =p (CO2)/p? (4)Kc =
? c (H2O) ? ? c (H2) ?33 Kp =
? p (H2O) ? ? p (H2) ?33
K?=
p (H2O)/p? 2)/? ? p (Hp?? ?33
??5.解:设?rHm、?rSm基本上不随温度变化。
??? = ?rHm ? T ·?rSm ?rGm?(298.15 K) = ?233.60 kJ·mol?1 ?rGm?(298.15 K) = ?243.03 kJ·mol?1 ?rGmlgK?(298.15 K) = 40.92, 故 K?(298.15 K) = 8.3?1040 lgK?(373.15 K) = 34.02,故 K?(373.15 K) = 1.0?1034
??6.解:(1) ?rGm=2?fGm(NH3, g) = ?32.90 kJ·mol?1 <0
该反应在298.15 K、标准态下能自发进行。
(2) lgK?(298.15 K) = 5.76, K?(298.15 K) = 5.8?105
??7. 解:(1) ?rGm(l) = 2?fGm(NO, g) = 173.1 kJ·mol?1
?= lgK1???fGm(1)? = ?30.32, 故 K1= 4.8?10?31
2.303 RT??(2)?rGm(2) = 2?fGm(N2O, g) =208.4 kJ·mol?1 ?= lgK2???fGm(2)? = ?36.50, 故 K2= 3.2?10?37
2.303 RT??(3)?rGm(3) = 2?fGm(NH3, g) = ?32.90 kJ·mol?1 ??= 5.76, 故 K3= 5.8?105 lgK3 由以上计算看出:选择合成氨固氮反应最好。
????8.解:?rGm = ?fGm(CO2, g) ? ?fGm(CO, g)? ?fGm(NO, g)
= ?343.94 kJ·mol?1< 0,所以该反应从理论上讲是可行的。
??9.解: ?rHm(298.15 K) = ?fHm(NO, g) = 90.25 kJ·mol?1 ? ?rSm(298.15 K) = 12.39 J·mol?1·K?1
??? ?rGm(1573.15K)≈?rHm(298.15 K) ?1573.15?rSm(298.15 K)
= 70759 J ·mol?1
lgK?(1573.15 K) = ?2.349, K?(1573.15 K) = 4.48?10?3 10. 解: H2(g) + I2(g)
2HI(g)
平衡分压/kPa 2905.74 ?χ 2905.74 ?χ 2χ
(2x)2= 55.3 2(2905.74?x)χ= 2290.12
p (HI) = 2χkPa = 4580.24 kPa