13、 大于 14、×10 15、变小
16 、阳 阴 正 负
17、电流密度;电极电位偏离平衡电极电位的现象;浓差极化,电化学极化。有电流
通过时,电极电位对平衡电位的偏离。 18、 >0, >0 19、 20、 ;
-4
四、写出下列电池中各电极上的反应和电池反应。
(1)解: (
): H2(g ,p1)
2 H+(a)+2e
2Cl-(a)
(+): Cl2(g ,p2) +2e
电池:H2(g ,p1) +Cl2(g ,p2) ===2 HCl(a)
(2)解:(): 1/2H2(g ,p1)
(+): Ag+(a2) +e
H+( a1)+ e
Ag(s)
电池:1/2H2(g ,p1) +Ag+(a2)═H+( a1)+Ag(s)
(3)解:(): Ag(s)+ I-(a1)
(+):AgCl(s) +e
AgI(s)+ e
Ag(s)+ Cl-(a2)
电池:AgCl(s)+I-(a1)═AgI(s)+Cl-(a2)
(4)解:():Pb(s) + SO42-(a1)
(+):Cu2+(a2)+2e
PbSO4(s)+ 2e
Cu(s)
电池:Pb(s) + SO42-(a1) +Cu2+(a2)═PbSO4(s)+ Cu(s)
(5)解:(): H2(p(H1)+2OH(a)
(+):HgO(s) +H2O +2e
2H2O+2e Hg(l)+ 2OH(a)
电池:H2(p(H1)+ HgO(s)═Hg(l)+ H2O
(6)解:(): 3H2(g ,p1)
6H+(a)+6e
2Sb(s)+ 3H2O
(+):Sb2O3(s)+6H+(a)+6e
电池:3H2(p(H1)+ Sb2O3(s)═2Sb(s)+ 3H2O
(7)解:():Fe2+(a2)
Fe3+(a1)+e
(+):Ag+(a3) +e
Ag(s)
电池:Fe2+(a2)+ Ag+(a3)═Fe3+(a1) +Ag(s)
(8)解:(): 2Na(Hg)(a3)
(+):HgO(s) +H2O +2e
2Na+(a1) + 2Hg +2e Hg(l)+ 2OH(a2)
电池:2Na(Hg)(a3) + HgO(s) +H2O═2Na+(a1)+3 Hg(l)++2OH(a2)
五、试将下述化学反应设计成电池。
(1)解: Ag(s) ∣Ag+(a1)║Cl-(a2) ∣AgCl(s)∣Ag(s) (2)解: Ag(s) ∣AgI(s)∣I-(a1)║Cl-(a2)∣AgCl(s) ∣Ag(s) (3)解: Pt∣H2(g ,p1)∣H+(aq)∣HgO(s)∣Hg(l) ∣Pt (4)解: Pt∣Fe3+(a3),Fe2+(a1)║Ag+(a2)∣Ag(s) (5)解: Pt∣H2(g ,p1)∣H+(aq)∣O2(g ,p2)∣Pt (6)解: Pt ∣I2(s)∣I-(a1) ║Cl-(a2)∣Cl2(g ,p1)∣Pt
六、计算题答案
1、解: 设273K时电池电动势为E (E ?E1) /(T ?T1)= ? ×10 -3V / K E = ? ×10设反应中 n = 2
ΔrGm = ? nFE = ?2× V×96500 C · mol= ? · mol ΔrSm = nF(?E -3
)P = 2×96500 C · mol×(?×10V / K) = ? / K· mol ?T -3
V /K(298K ? 273K ) + =
ΔrHm = ΔrGm +TΔrSm
= ?mol + 298K×(? / K· mol)×10-3= ? kJ · mol
QR = TΔrSm = 298K×(? / K· mol)×0-3 = ? kJ · mol 2、(1)根据式 ??G?Kcell,电导池系数
Kcell=κ(KCl)×1=κ(KCl)×R(KCl) G(KCl)=0.140877S×m-1×150.00Ω=21.13m-1·dm–3HCl溶液的电导率为
?(HCl)?Kcell/R(HCl)?21.13m?1/51.4??0.4111S?m?1 ·dm–3溶液的摩尔电导率为
Λm(HCl)??(HCl)/c(HCl)?0.4111S?m?1/10mol?m?3?0.04111S?m2?mol?1
3、解:(-) H2(p) (+) Cl2 p)+e
H+ mol·kg-1)+e Cl( mol·kg-1)
H2(p)+ Cl2 p) === HCl mol·kg-1) E=E(Cl|Cl2|Pt)- E(H+|H2|Pt)-
= E(Cl|Cl2|Pt) -
4、解: 电池反应:Zn+ PbSO4(s)===Pb+ ZnSO4(b= mol·kg-1, (1)E= E(SO2-2+4|PbSO4|Pb) E(Zn|Zn) = E(SO2-4|PbSO4|Pb) E(Zn2+|Zn) = E(SO2-4|PbSO4|Pb) E(Zn2+|Zn)
= E(SO2-4|PbSO4|Pb)
E(Zn2+|Zn) ×
E(SO2-4|PbSO4|Pb)=E + E(Zn2+|Zn) + ×10-3) =V=
V
(2)E= E
lga=(EE)/ ==
a=×10-3
= ab/ b=
= 5、解:b±(SnCl2)=[×(2×+2]1/3 mol·kg-1
= mol·kg-1
a±(SnCl2)=γ±(SnCl2)×b±(SnCl2)/ b =×= 6、解: 设计可逆电池:Pt| Sn4+,Sn2+|| Fe3+,Fe2+|Pt
E=RTlnK/2F =
lga2(Fe3+)=-2 E/ ==-
lg a(Fe3+)=-
=
a(Fe3+)=×10-11 7、解:溶液的离子强度: I=
=(3××12+×32)mol·kg-1
= mol·kg-1 根据 -ln
[ K1/23Fe(CN)6 ]=- kg1/2
=-1/2·kg1/2×|1×(-3)|?0.06mol?kg?1 = [ K 3Fe(CN)6 ]=
8、 (1)Zn+2AgCl(s) === ZnCl2(b=·kg-1)+2Ag (2)lgK=zFE/=
=
K=×1033 (3)E=E- E-
= E-
[lg
+3lg]= E-{lg[4
=
=
=
9、解:== (
× S·m-1=×10-5 S·m-1
m
=/c=
S·m2·mol-1= S·m2·mol-1
?-42m= + ×10 S·m·mol-1 =×10-4 S·m2·mol-1 所以, == = 10、解:PbSO4水溶液无限稀释的摩尔电导率:
Λ ?m?PbSO4??2Λ ??12????12-?m??2Pb???2Λ m??2SO4?? = (2×70+2××10
4 S
m2
mol
1 =×104 Sm2 molΚ ?2?C?SO2??/?c??2sp?PbSO4??C?Pb?4
求得PbSO4的溶解度:
c = c (Pb2+) =c (SO42-)= Κ ?spC?? ×104 mol dm3 ]+3lg=-
1
}
PbSO4的电导率:
?κ?AgCl??Λ m?PbSO4? c=×104××104×103 S m1
=×10
4 S
m
1
饱和溶液的电导率:
κ(溶液) =κ(PbSO4) +κ(H2O) = +×104 S m1 =×104 S m1