, : α = 1 i = ν (, KCl NH4Cl ν = 2, K2SO4 CuCl2 ν = 3, AlCl3 ν = 4 ..). i < ν.
, . , , , , i = 2. . NaCl i . , , .
, . , . . . ( ) , , .. . , . , ; , - , . , , , . , , , .. α . , , .
. , . , . , , . .
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g, , .
z+ z ; e (4.81010 ...); (1,381016 / = 1,381023 /); ; ξ .
g, .. , . ξ . , , , . g , . . , = 298 g = 3,5710-8= 3,57A.
g < 3,57 A , g 3,57A .
, . . 1907 . , (∆G .) , . , , . . . , .
a = f,
a , f .
. , . f , . f < 1 , . , , f ≈ 1.
+ ; :
a + = f + +; = f
a
a = (a + )1/2
f = (f + f )1/2
ν+ν−, ν+ ν− , a
a = [(a +)ν+ ( )ν−]1/ν,
f
f = [(f +)ν+ (f )ν−]1/ν
, . , .
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f. , I. , . , , :
I = 1/2(C1z12 + C2z22 +... + Cnzn2).
, (1,1 ) (z+ = z− = 1) .
: .
, . , , . , , . . , . , .
. 16 , . . , - l ; N2SO4 ul2, , 0,1; - uSO4 .
. 16. ( ).
, , . , , 1,1 f + =f . l . , f K+ f Cl .
f l = [((f +)1/2 (f )1/2)]1/2 = f K+ = f Cl
, .
,
f Ml = [(f M+)(f Cl)]1/2 = [(f M+)(f Kl)]1/2,
f M+ = f 2l2 / f 2l
f 2l2 = [(f M2+)(f Cl)2]1/3 = [(f M2+)(f Kl)2]1/3,
f M2+ = f 3l2 / f 2l
. ,
f K2SO4 = [(f K+)2 (f SO42)]1/3 = [(f Kl)2 (f SO42)]1/3,
f SO42 = f 3K2SO4 / f 2l
f Cu2+ uSO4, .
f CuSO4 = [(f Cu2+)(f SO42)]1/2,
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, f SO42 ,
f Cu2+ = [(f 2 CuSO4)(f 2l) / f 3K2SO4
(mean salt method).
. . (1923) . - , , :
lg fi = (A zi2I 1/2) / (1 + iBI 1/2 )
zi I ; - . . 7 ( 1 ).
7.
- ( )
, | (´10-8) | , | (´10-8) | ||
0,4883 | 0,3241 | 0,5175 | 0,3297 | ||
0,4921 | 0,3249 | 0,5221 | 0,3305 | ||
0,4960 | 0,3258 | 0,5271 | 0,3314 | ||
0,5000 | 0,3262 | 0,5319 | 0,3321 | ||
0,5042 | 0,3273 | 0,5371 | 0,3329 | ||
0,5085 | 0,3281 | 0,5425 | 0,3338 | ||
0,5130 | 0,3290 |
i " " . i ( ) . 8. i , . , i , . , , . i, .
8.
i
i (´108) | |
2,5 | Rb+, Cs+, NH+4 T1+, Ag+ |
3,0 | K+, Cl‾, Br‾, I‾, NO3‾ |
3,5 | OH‾, F‾, HS‾, rO3‾, IO4‾, n4‾ |
4,0-4,5 | Na+, 3‾, H2PO4‾, SO3‾, Hg22+, SO42‾, SeO42‾, CrO42‾, HPO42‾, PO43‾ |
4,5 | Pb2+, CO32‾, SO32‾, MoO42‾ |
5,0 | Sr2+, Ba2+, Ra2+, Cd2+, Hg2+, S2‾, WO42‾ |
Li+, Ca2+, Cu2+, Zn2+, Sn2+, Mn2+, Fe2+, Ni2+, Co2+ | |
Mg2+, Be2+, | |
H+, Al3+, r3+, | |
Th4+, Zr4+, Ce4+, Sn4+ |
, 0,05 /. , 0,05, . - ; - , , . , - :
lg fi = A zi2I 1/2
, :
lg fi = 0,5 zi2I 1/2
, , :
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lg f = A|z+ z |I 1/2
( | | ).
. 17 , - . , fi , , - ; , 0,02. NO3‾, , - , I = 0,1. SO42‾ 2+ - . , , , , 0,05.
. 17. . , . I < 0,01 fi, - , ( ).