, Ag+, Hg22+, Pb2+.
:
Ag+ [Kr]5s14d10; Hg22+ [Xe]6s14f145d10; Pb2+ [Xe]4f146p25d10.
(1/1HCl)=2,0/3.
Ag+, Hg22+, Pb2+ 䳿 - :
Ag+ + Cl− → AgCl↓; Hg22+ + 2Cl− → Hg2Cl2↓; Pb22+ + 2Cl− → PbCl2↓;
, :
AgCl↓ + 2HCl → H2[AgCl3]; PbCl2↓ + HCl → H[PbCl3].
PbCl2 200. AgCl Hg2Cl2 . Pb2+ Ag+ Hg22+.
䳿 Hg2Cl2 , , :
Hg2Cl2 + 2NH4OH → [Hg2NH2]Cl↓ + NH4+ + Cl +2H2O;
[Hg2NH2]Cl → [HgNH2]Cl↓ + Hg.
ij Ag+ Hg22+ : Ag+ [g(NH3)2]+, Hg22+ [HgNH2]Cl.
4.2.1. Ag+
Ag+ .
1. Ag+ NaOH KOH. AgOH, 䳺 :
Ag+ + OH → AgOH↓;
2AgOH → Ag2O↓ + H2O.
Ag2O :
Ag2O + 4NH4OH → 2[g(NH3)2] + 3H2O.
, NH4OH
. | , |
[NH4]+ −. , - , [NH4]+ [NH4]+ =61010. г +
[NH4]+ NH3 + H+ , - 2 H+ + , .
2. Ag+ - - :
2Ag+ + CrO42 → Ag2CrO4↓.
=5,5-7,5.
Ag+ [g(NH3)2]+:
Ag2CrO4 + 4NH3H2O → 2[g(NH3)2]+ + CrO42 + 4H2O.
. Ag2Cr2O7, , .
|
|
, CrO42- (, Pb2+, Ba2+ ), Ag+ .
3. - (Br−, I−) Ag+ AgBr AgI :
Ag+ + r− → AgBr↓;
Ag+ + I− → AgI↓.
:
AgI↓ + I → [AgI2],
:
{m(AgI)nI∙(nx)K+}−xK+.
4.2.2. Pb2+
1. Pb2+ :
Pb2+ + 2− → Pb()2↓,
, :
Pb()2↓ + 2+ → Pb2+ + 22;
Pb()2↓ + 2Na+ + 2OH → 2Na+ + [Pb()4]2;
[Pb()4] PbO22 + 2H2O.
, Na2PbO2.
, , Pb2+, , Pb()2 .
2. 䳿 - Pb2+ PbSO4 ((PbSO4)=1,6108. Pb2+ () .
PbSO4 :
PbSO4 + 4OH− → PbO22 + 2H2O + SO42− .
(w=30%). [Pb(CH3COO)2PbSO4]:
2PbSO4 + 2CH3COO− → [Pb(CH3COO)2PbSO4] + SO42.
PbSO4 , SO42, , SO4 : + + SO42 SO4−.
3. Pb2+ :
Pb2+ + CrO42 → PbCrO4↓.
:
PbCrO4 + 4NaOH → Na2[Pb(OH)4] + Na2CrO4;
PbCrO4 + 4OH → [Pb(OH)4]2 + CrO42,
.
䳿 Pb2+ Pb(OH)2 Pb(OH)n (n ), .
4. Pb2+ 䳿 -:
Pb2+ + 2I− → PbI2↓.
- .
PbI2 (( CH3COO)=2/3) , .
PbI2 =3-5.
PbI2 . [PbI4]2:
PbI2 + 2KI → K2[PbI4].
Pb2+ - .
5. Pb2+ , , - :
|
|
Pb2+ (Fe3+, Cu2+, Ni2+, Zn2+ .), .
6. - .
4.2.3. [g2]2+
()- [HgHg]2+ 1+.
1. 䳿 [g2]2+ Hg2Cl2 ,
[NH2Hg]Cl + Hg. :
3[NH2Hg]Cl + 3Hg + 14H+ + 14NO3−→ 6Hg2+ + 12NO3− + 3NH4+ + 3Cl− + 4H2O +2NO.
2. [g2]2+ () , :
[g2]2+ + 2OH → Hg2O↓ + H2O.
Hg2O HgO Hg.
3. ()- [g2NH2]Cl.
4. - [g2]2+
() | , |
.
5. [g2]2+ , Sn2+ () . SnCl2
.
Hg2Cl2:
[g2]2+ + 2l → Hg2Cl2↓,
䳺 Sn2+:
Hg2Cl2 + Sn2+ → 2Hg↓ + Sn4+ + 2l.
³ .
6. [g2]2+ . ̳ , Hg2(NO3)2. :
Hg2(NO3)2. + u → u(NO3)2. + 2Hg↓.
, . .
7. [g2]2+ :
Hg2(NO3)2, (w=2%) . .
Hg2+ CrO42, [g2]2+ , , .
Cu2+, Fe2+, Fe3+, Cr3+, Co2+, , [g2]2+ .
8. 䳿 [g2]2+ Hg2I2 - :
[g2]2+ + 2I → Hg2I2↓,
:
Hg2I2 + 2I → 2[g4] + Hg↓.