KatAn → Kat+ + An‾
: (-) : (-)
Kat+;+(2) An‾; ‾(2)
:
Katn+ + nē → Kat0 Ann‾ - nē → An0
22 + 2ē → 20 + 2 ‾ 22 - 4ē → 20 + 4+
, -
φ >! φ <!
(2) - (O2) -
, ,
, ,
. .
φ2/2+ = 0,059 - η2 φ2/‾ = 1,23 0,059 + η2
() ()
:
1. , Kat+ An‾, , .
2. , :
φn+/0 = φ0 0,059/n lg[Men+]
φ2/2+ = 0,059 - η2
()
φ2/‾ = 1,23 0,059 + η2
()
3. :
, ( Cu2+, Hg2+, Ag+, Au3+, Pt2+ .) .
, (Mn2+, Zn2+, Cr3+, Fe2+, Cd2+, Ni2+, Sn2+, Pb2+) , .
(Li+, Rb+, K+, Ba2+, Ca2+, Na+, Mg2+, Al3+) , .
22 + 2ē → 20 + 2 ‾
4. :
) , (Cl‾, Br‾, I‾, S2-, CN‾).
) (SO32-,NO3‾, PO43-, CO32- F‾), ,
22 - 4ē → 20 + 4+
5. :
m = ݷIτ;
F
m ();
( = Ar/);
I ();
τ (.);
F (96500 )
.
KatAn → Kat+ + An‾
: (-) : (-)
Kat+;+(2) An‾; ‾(2)
:
Katn+ + nē → Kat0 Ann‾ - nē → An0
2+ + 2ē → 20 4‾ - 4ē → 20 + 22
0 nē → Men+
|
|
( )
:
1. , .
2. (, ..), ( ).
: ǔ
1
Na2SO4, = 7, .
Na2SO4 → 2 Na+ + SO42‾
- -
Na+;+(2) SO42‾; ‾(2)
:
Na+ + ē → Na0 2SO42‾ - 2ē → S2O82-
22 + 2ē → 20 + 2 ‾ 22 - 4ē → 20 + 4+
φ Na+/Na = - 2,71 (.1) φ 2SO42-/S2O82- = + 2,05 (.2)
φ 2+/2 = - 0,059 - η2 φ2/‾ = 1,23 0,059 + η2
() ()
η2 = 0 (. 4) η2 = 1,17
() ()
φ 2+/2 = - 0,0597 0 = - 0,41 φ2/‾ = 1,23 0,0597+1,17 = 1,987
φ 2+/2 > φ Na+/Na=> φ 2SO42-/S2O82 > φ2/‾ =>
.
‾ - + -
22 + 2ē → 20 + 2 ‾ 22 - 4ē → 20 + 4+
Na2SO4 + 2 H2O → H2↑ + O2↑ + Na2SO4
(K) (A)
2 H2O → H2↑ + O2↑
(K) (A)
2
CuSO4, =6 (: , : u).
CuSO4 → Cu2+ + SO42‾
: - : -
Cu2+; +(2) SO42‾; ‾(2); Cu0.
:
Cu2+ + 2ē → Cu0 2SO42‾ - 2ē → S2O82-
22 + 2ē → 20 + 2 ‾ 22 - 4ē → 20 + 4+
Cu0 - 2ē → Cu2+
φ Cu2+/Cu0 = + 0,34 (.1) φ Cu2+/Cu0 = + 0,34
φ 2+/2 = - 0,059 - η2 φ2/‾ = 1,23 0,059 + η2
() ()
φ 2SO42-/S2O82- = + 2,05 (.2)
η2 = 0 (. 4) η2 = 1,05
() (u)
φ 2+/2 = - 0,0596 0 = - 0,354 φ2/‾ = 1,23 0,0596+1,05 = 1,926
φ 2+/2 < φ Cu2+/Cu0=> - φ 2SO42-/S2O82 > φ2/‾ > φ Cu2+/Cu0 =>
().
Cu2+ + 2ē → Cu0 Cu0 - 2ē → Cu2+
+ - ‾ - -
uSO4 + 2 H2O + Cu → Cu0 + Cu2+ + H2SO4 + 2OH‾
() (A)
13. -
.
: , , , .. () () . I .
(1) () : (K) :
|
|
Oxe Red
0 - nē ↔ 2+ + nē ↔
- - ,
- -
.
,
: 1. ( )
2. ,
( )
.
(<7) (>7)
(=7)
1) 2+ + 2ē ↔ 2↑ 1) 2+ + 2ē ↔ 2↑
2 2 + 2ē ↔ 2↑ + 2 ‾
2) 2 +4ē + 4+ ↔ 22 2 +4ē + 22 ↔ 4‾
:
1. 2, .
2. , (φ0max>).
3. , , .
4. :
φ2/2+ = 0,186 0,059 - η2
()
φo2/2o- = 1,21 0,059 - η2
()
:
»
= 2, .
: Fe/Zn, = 2, .
1. φ ( . 3) =2
φFe0/Fe2+ = - 0,32
φZn0/Zn2+ = -0,84
2. .. φZn0/Zn2+ < φFe0/Fe2+, => Zn (A), Fe (K).
3. : () : Zn0 - 2ē ↔ Zn2+
() : 2+ + 2ē ↔ 2↑ ( )
2 +4ē + 4+ ↔ 22 ( )
4. η2 = 0,34 (. 4)
Fe()
η2 = 1,07
Fe()