1. - NaNO2, K2CO3, FeSO4, ZnCl2 . . . .
. , , , , + . ( NaNO2 K2CO3) , . ( (2) FeSO4 ZnCl2) , , . .
1) NaNO2 = Na+ + NO2 - ,
NO2 + 2 <=> NO2 + - .
, .. . , , :
, , 1,110-14, kd : kd(HNO2) = 6,910-4. kg :
= 1,610-11.
, kd >> kg, , .. , = 7.
2) 23 = 2+ + 32 - , ,
32 + 2 <=> 3 + - 1- .
- , ≥ 7.
kg1 = [HO3][OH]/[O32][H2O] = kW/kd2(H2O3).
kg1, 9:
kg1 = (1,110-14)/(4,710-11) = 2,3410-4.
, kg1 >> kd2, .
- ? ,
3 + 2 <=> 23 + - 2- , , > 7.
:
kg2 = [H2O3][OH]/[O3][H2O] = kW/kd1(H2O3).
, :
kg2 = (1,110-14)/(4,510-7) = 2,4410-8.
, kg2 < kd1, . ≥ 7.
3) FeSO4 = Fe2+ + SO42 - .
, Fe(OH)2 - , H2SO4 2- , I- - :
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Fe2+ + SO42 + 2 <=> (FeOH)+ + (HSO4).
:
kg1 = [(FeOH)+][ (HSO4)]/[Fe2+][SO42][H2O] = kW/kd2(Fe(OH)2)kd2(H2SO4).
(2) , :
kg1 = (1,110-14)/(5,510-8)(1,210-2) = 1,6710-5.
kg1 > kd2(Fe(OH)2), Fe2+ - (FeOH)+, SO42, , .. kd2(H2SO4) > kg1. : :
Fe2+ + 2 <=> (FeOH)+ + + - I- , , ≤ 7.
:
kg1 = [(FeOH)+][H+]/[Fe2+][H2O] = kW/kd2(Fe(OH)2) = (1,110-14)/(5,510-8) = 0,210-6.
, Fe2+.
(FeOH)+ + 2 <=> Fe(OH)2 + H+ - II- , , <7. :
kg2 = [Fe(OH)2][H+]/[(FeOH)+][H2O] = kW/kd1(Fe(OH)2),
kg2 = (1,110-14)/(1,210-2) = 9,1710-13.
(2) , , kg2 << kd1(Fe(OH)2), , , , , ≤ 7.
4) ZnCl2 = Zn2+ + 2Cl- - ,
Zn2+ + H2O <=> (ZnOH)+ + H+ -1- , ≤ 7;
kg1 = [(ZnOH)+][H+]/[Zn2+][H2O] = kW/kd2(Zn(OH)2).
, :
kg1 = (1,110-14)/(4,910-7) = 2,2410-8.
, , + , ≈ 7.
(ZnOH)+ + H2O <=> Zn(OH)2 + H+ - 2- ,
kg2 = [Zn(OH)2][H+]/[(ZnOH)+][H2O] = kW/kd1(ZnOH)2).
, kg2 = (1,110-14)/(1,310-5) = 8,4610-10.
kg2 << kd1(ZnOH)2), , , .
: ) NaNO2 , , = 7, .. kd >> kg;
) 23 , , ≥ 7;
) FeSO4 , , ≤ 7;
) ZnCl2 , .. kg1 kd2 , , ≈ 7.
2. Al(NO3)3 Na2S. - . .
. , , . :
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Al(NO3)3 = Al3+ + 3NO3; Na2S = 2Na+ + S2.
Al3+ - S2. :
Al3+ + H2O <=> (AlOH)2+ + H+; S2 + H2O <=> (HS) + OH.
, , , , . + 2. , :
(AlOH)2+ + H2O <=> (Al(OH)2)+ + H+,
, (Al(OH)2)+ + H2O <=> Al(OH)3↓ + H+;
(HS) + 2 <=> H2S↑ + .
, - :
2Al3+ + 3S2- + 6H2O = 2Al(OH)3 ↓ + 3H2S↑;
2Al (NO3)3 + 3Na2S+ 6H2O = 2Al(OH)3 ↓ + 3H2S↑ + 6NaNO3.
:
kg(Al3+) = kW/kd3kd2kd1(Al(OH)3); kg(S2-) = kW/kd2kd1(H2S).
, :
kd1(Al(OH)3) = 8,310-9; kd2(Al(OH)3) = 2,110-9; kd3(Al(OH)3) = 1,010-9;
kd1(H2S) = 1,010-7; kd2(H2S) = 2,510-13.
, , k2 = 1,110-14, Al3+ S2:
kg(Al3+) = (1,110-14)/[(1,010-9)(2,110-9)(8,310-9)] = 6,311011;
kg(S2) = (1,110-14)/[(2,510-13)(1,010-7)] = 4,40105.
.
: 2Al (NO3)3 + 3Na2S+ 6H2O = 2Al(OH)3 ↓ + 3H2S↑ + 6NaNO3.
Al(OH)3 H2S, kg(Al3+) = 6,311011; kg(S2-) = 4,40105.
3. , 0,001 Fe2(SO4)3.
. (3) : Fe2(SO4)3 = 2Fe3+ + 3SO42;
Fe3+ + SO42 + H2O <=> (FeOH)2+ + (HSO4) - 1- , - ;
(FeOH)2+ + H2O <=> (Fe(OH)2)+ + H+ - 2- ;
(Fe(OH)2)+ + H2O <=> Fe(OH)3↓+ H+ - 3- . , , .
1- (- ) :
kg1 = [(FeOH)2+][ (HSO4)-]/[Fe3+][SO42-][H2O] = kW/kd3(Fe(OH)3)kd2(H2SO4).
(3) , : kd3(Fe(OH)3) = 1,510-12; kd2(H2SO4) = 1,210-2 kg1 = (1,110-14)/[(1,510-12)(1,210-2)] = 0,61.
, kg1 >> kd3(Fe(OH)3) kg1 > kd2(H2SO4), Fe2+ SO42 - (FeOH)2+ - (HSO4), .. .
:
kg2 = [Fe(OH)2+][H+]/[(FeOH)2+][H2O] = kW/kd2(Fe(OH)3).
kd2(Fe(OH)3) = 1,810-11,
kg2 = (1,110-14)/(1,810-11) = 0,6110-3.
kg2 >> kd2(Fe(OH)3), , .
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kg3 = [Fe(OH)3][H+]/[Fe(OH)2+][H2O] = kW/kd1(Fe(OH)3)
kd1(Fe(OH)3) = 4,810-11 kg3 = (1,110-14)/(4,810-11) = 0,2310-3.
kg3 >> kd1(Fe(OH)3), , Fe3+ . - :
Fe3+ + SO42 + H2O = Fe(OH)3↓+(HSO4) + H+,
Fe2(SO4)3 + H2O = Fe(OH)3↓ + H2SO4.
, ( 26 ), :
kg = kg1kg2kg3 = (0,61)(0,6110-3)(0,2310-3) = 8,5610-4.
kg β : kg = β2μ/(1 - β).
:
β210-3 = (8,5610-4)(1-β) β2 + 8,56β 0,856 = 0, β = 0,1 β = 10%.
:
= 7 + ½kd2(H2SO4) - ½pkd1(Fe(OH)3).
:
= 7 - ½ℓg(1,210-2) + ½ℓg(4,810-11) = 7 - ½(-2 + 0,08) + ½(-11 + 0,68) = 7 + 0,96 - 5,12 = 2,84.
: Fe(OH)3, β = 10%; = 2,84.
4. 10,5 11. , .
. , , . , :
n =+ + An An + 2 <=> n + .
, μ() = μ(n)
kg = μ2()/μ(An).
, , μ() = βμ(An), ,
μ(+) = k2/μ() μ(+) = k2/βCμ(An).
k2 μ(An) , :
μ(+)1/μ(+)2 = β2/β1.
μ(+)1= 10-10,5 μ(+)2 = 10-11, β2/β1= 10-10,5/10-11 = 3,16. , 3,16 .
, , .. kg = β2Cμ,
(β2/β1)2 = kg2/kg1.
kg2/kg1 :
kg2/kg1 = (3,16)2 = 9,99 ≈ 10.
, 10 .
: 3,16 , 10 .
5. 0,2 , 1 3,4 , 93%, kd(HCOOH) = 1,810-4. .
. , , .
HCOONa. - , . :
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1) <=> + +,
2) HCOONa = HCOO + Na+,
3) HCOO + H2O <=> HCOOH + OH.
(2) (1) (3).
P :
= pkd() - ℓg [Cμ()/Cμ(HCOO)].
:
Cμ(HCOONa) = m(HCOONa)/[M(HCOONa)V(-)]; Cμ(HCOONa) =3,4/(671)=0,05 /. Cμ(HCOO) = α Cμ(HCOONa) = (0,93)(0,05) = 0,046 /.
:
= -ℓg(1,810-4) - ℓg(0,2/0,046) = (4 - 0,25) 0,64 = 3,11.
, ( ) + (3) (1) . ( 3), ( 1), .
: = 3,11.
6. HCl NaOH , 1 1 2 .
. . n , 1 , ( ) ( ) .
= 14 kd() + ℓg [Cμ()/μ()].
kd(NH4OH) = 1,810-5, μ(NH4OH) = 2 /, μ(NH4Cl) = 1 /, :
= 14 + ℓg(1,810-5) + ℓg(2/1) = 14 5 + 0,25 + 0,30 = 9,55.
HCl . HCl 1
NH4OH + HCl <=> NH4Cl + H2O.
μ(NH4Cl) = (1 + ) /, μ(NH4OH) = (2 ) /. , .. = 8,55. :
8,55 = 14 + ℓg(1,810-5) + ℓg[(2- x)/(1+ x)];
ℓg[(2 - x)/(1 + x)] = -0,7; (2 - x)/(1 + x) = 10-0,7 = 0,2; 2 x = 0,2(1 + x); x = 1,50.
, HCl 1,50 /.
NaOH . NaOH 1
NH4Cl + NaOH <=> NH4OH + NaCl.
μ(NH4Cl) = (1 ) /, μ(NH4OH) = (2 + ) /, , .. = 10,55. :
10,55 = 14 + ℓg(1,810-5) + ℓg[(2 + )/(1 )]; ℓg[(2 + )/(1 )] = 1,3;
(2 + )/(1 ) = 101,3 = 19,95; 2 + = 19,95(1 y); y = 0,86.
, NaOH 0,86 /.
: nHCl = 1,50 1 , nNaOH = 0,86 1 .