1. , Cd(OH)2, 298,15 K −0,55 . .
. = 298,15 K
Cd(OH)2 , , Cd2+.
lg = = −4,98.
= 1,04∙10−5; [Cd2+] = 1,04∙10−5 //
Cd(OH)2 ,
Cd(OH)2 () ⇄ Cd2+() + 2−().
, 2 Cd2+ : 1,04∙10−5 ∙ 2 = 2,08∙10−5 /.
= [Cd2+]∙[OH−]2.
= 1,04∙10−5 ∙ (2,08∙10−5)2 = 4,50∙10−15 (/)3.
= 4,30∙10−15 (/)3.
2. , , :
(−) Ag | Pb | Pb2+ || Cu2+ | Cu | Ag (+).
, , = 10−2, = 10−4? , .
. : . , .
0 = − = 0,337 (−0,126) = 0,463 > 0,3,
, , . :
(−): Pb → Pb2+ + 2ē
(+)K: Cu2+ + 2ē → Cu.
= 298,15 K
= −0,126 + lg10−2 = −0,185
= 0,337 + lg10−4 = 0,219 .
= − = 0,219 (−0,185) = 0,404 ≠ 0
, , . .
, -
Pb + Cu2+ ⇄ Pb2+ + Cu.
, (2). K
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∆r G 0298= −R∙298,15∙2,3∙lg K ,
∆r G 0298= − nFE 0.
F R ,
lg K = = = 15,69,
K = 4,90∙1015.
, .. .
, ..
A = −∆r G = nFE = 2∙96485,3∙0,404 = 77960,12 .
3. , : ZnBr2 Cu(NO3)2. ( ) . , .
. ( )
ZnBr2 → Zn2+ + 2Br−
Cu(NO3)2 → Cu2+ + 2NO3−.
, : (Br− NO3−), (Zn2+ Cu2+) (2). . 2 Br− NO3−, − 2 Zn2+ Cu2+.
:
22 → 2↑ + 4++4ē < 0,993 ( > 4)
(+): 2Br− → Br2 + 2ē = 1,087
NO3−-
, .
, - , , . NO3.
:
22 +2ē → 2↑ + 2− < −0,236 ( > 4)
(−)K: Zn2+ + 2ē → Zn = −0,763
Cu2+ + 2ē → Cu = 0,337
, . , , , , . , Zn2+.
2Br− + Cu2+ → Br2 + Cu.
, .
- :
ZnBr2 + Cu(NO3)2 → Br2 + Cu + Zn2+ + 2NO3−.
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4. = 298,15 K 5 1 NaCl, 12. . ( ) . 1.
. NaCl , , .. 7 [H+] = [OH−] = 10−7 /. : Na+ Cl− 2. : = 1,360 , = −2,714 , = −0,413 , = 0,816 , (. 3):
(+) : 2Cl− → Cl2↑ + 2ē
(−) K: 22 +2ē → 2↑ + 2−.
− :
= 14 = 14 12 = 2
= lg
= 10−2; = 10−2 /.
a = Cγ .
= 1,10∙10−2 /,
− − ( ).
−-, ,
n − = ( − 10−7)∙ V = (1,1∙10−2 − 10−7)∙1 = 1,1∙10−2 .
: , . .. , 12,225 / ,
= 1,1∙10−2 ∙ 12,225 = 0,134 .
= 212 = 3,5 .
= 212 .