, : 2+ + 2 = 2, .
:
1. , .
2. () , .
3. , , . . , .
: Zn + 2HCl = ZnCl2 + H2
Ű , Ű 25 , , 1 /.
- . - : - ?
- - .
- . :
(Ox/Red) = Ű(Ox/Red) + ,
(Ox/Red) - - ( )
Ű(Ox/Red) -
R (8,324 /∙)
T
F (96485 /)
n
a(Ox) a(Red)
. ( ) :
Ox/Red = ŰOx/Red +
= 298 , R F, (ln(a) = 2,3∙lg(a)) :
(Ox/Red) = Ű(Ox/Red) +
/ , [Red] :
(n+/Me) = Ű(n+/) + ln[n+] = Ű(n+/) + ∙ ln[n+]
-, .
, : n4- +8+ + 5- = n2+ + 42 :
, (Pt, 2[0,101 ] | +[a= 1]), 0,101 . + , 1, ( . .).
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( 2+ + 2 = 2), (2) , :
(+/2) = 0 (+/2) + 0,059 ∙ lg[H+].
, 0 (+/2) , lg[H+] = - :
(+/2) = - 0,059 ∙ .
:
2 + 4+ + 4 = 22 0 = 1,228 .
:
= 0 +0,059 ∙ lg[H+] + (0,059/4) ∙ lgP(O2), = 0 - 0,059 ∙ + (0,059/4) ∙ lgP(O2)
P(O2) . , :
= 0 - 0,059 ∙
, , , , . , . , . , - .
, . .
, , , . . , (...) .
(...) ():
ε = φ φ
- , .., , , , ... ε0 . , , :
ε0 = φ0 φ0
, , , ..:
φ0 > φ0
; .,
Pt, H2|HCl||CuCl2|Cu|Pt
( , 1 u12 ).
- () (.3.1).
- :
(-) [Zn/Zn(SO4)2||KCl|Cu/Cu(SO4)2] K (+).
|
|
(): Zn0 2 = Zn2+
(): Cu2+ + 2 = Cu0
KCl, , , (K+,Zn2+), - . (Cl-, SO42-), - . .
- :
Zn0 + Cu2+= Zn2+ + Cu0
, , , .
(-)
. 3.1. -
: = 0 + lg ;
: = 0 + lg = 0 + lg [Cu2+];
= 0 + lg = 0 + lg [Zn+2].
, : 0Zn2+/Zn = -0,763B, E0Cu2+/Cu = 0,337B.
, , .
(q) ...:
max. = ε∙q, q = n∙F, n , F , : F = e∙NA.
:
Amax. = - ΔrG
:
nFε = - ΔrG
... (ε0) ΔrG0, :
nFε0 = - ΔrG0.
, ΔrG0 :
ΔrG0 = -2,3RT∙lgK
:
zFε0 = 2,3RT∙lgK
:
nFε0 = - ΔrG0 - . , ΔrG0 <0, .. nFε0 >0, ε0 >0.
: ε0 = φ0 φ0, : φ0 φ0 >0 φ0 > φ0.
ΔG298 >> 0 , , (φ - φ) << 0 , .
, - , , .
, (Mn2+ - , I2 - ):
2 Mn2+ + 8 H2O + 5 I2 = 2 MnO4- + 16 H+ + 10 I-
:
φ - φ = φ (MnO4- / Mn2+) - φ (I2/ I-) = + 0,535 - (+ 1,531) = - 0,996
, - - - :
2 MnO4- + 16 H+ + 10 I- = 2 Mn2+ + 8 H2O + 5 I2
φ - φ = + 1,531 - (+ 0,535) = + 0,996
, (φ - φ) >> + 0,4 , - (.. , 99,0 99,9%). , . (φ - φ) . (φ - φ) (-0,4) ÷ (+0,4), . - . ( , , - ). , , (φ - φ). , .
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(), .
- - . , , - .
- (, , ), - (, , ). , CuCl2 , , :
CuCl2 → Cu2+ + 2Cl-
Cu2+ + 2e = Cu0
2Cl- - 2 = Cl2
( , , 2SO4):
, . , , ( Li+, Cs+, K+, Ca2+, Na+, Mg2+, Al3+) O−II ( ClO4−, SO42−, NO3−, PO43−, CO32−, SiO44−, MnO4−), . , - , . . : , , , . , , , . : ( ) , , . , , , . :
:
m
Q ,
F = 96 485,3383(83) −1
|
|
M
z ( ).
, M/z .
M, F z , Q, m.
Q, F z , M/z ( ), m.
:
Q = It
:
:
n ( ): n = m/M
t .
Q I() :
t .
, - - , . , .