Pb2+, Hg+, Ag+. . , . Pb2+, Hg+, Ag+. .
ó (I) . ó b()2 , +, - -:
Pb2+ + 2OH-↔ Pb(OH)2 + 2H2O ↔ 2H+ + [b ()4]2-
(II) [b()4]2-. . (II) . -, Pb(OH)2 , . Pb(OH)2 , :
Pb(OH)2 + 2HNO3 = Pb(NO3)2 + 22O.
(II) -. г , b()2 . 䳿 :
2[b()4] + 2NaOH = Na2[Pb()4] + 22O
b()2 + 2NaOH = Na2 [b()4]
. Pb2+, Ag+ Hg22+ . Ag + , CN-, SO32- . (AgCl, AgBr ) , .
. 䳿 PbCl2, AgCl, Hg2Cl2, b2+ . . . . ͳ . ( ) , '. - - ' . (II) , (II) b - .
II
Ag+
1. Cl, KCl.
Cl¯ Ag+ AgCl. 2 AgNO3 2 l. 5 , 6 :
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AgCl + 2NH3 = [Ag(NH3)2]Cl
[Ag(NH3)2]Cl + 2HNO3 = 2NH4NO3 + AgCl
2. KJ.
J¯ Ag+ AgJ.
.
3. K2CrO4.
CrO42- Ag+ Ag2CrO4, HNO3 NH4OH.
. 2-3
AgNO3 3-4 1-2 K2CrO4.
.
Hg22+
1. NH4OH.
䳿 , :
Hg
Hg2Cl2 + NH4OH →[Hg2NH2 Cl] [HgNH2]Cl
2. ʲ.
ʲ Hg22+ - :
Hg22+ + 2 ‾ → Hg2I2 ↓
3. 2CrO4.
CrO4 2 ‾ , , Hg22+ - :
Hg22+ + CrO42‾ = Hg2CrO4↓
CH3COOH, HNO3.
Pb2+
1. ʲ.
‾ - PbI2.
Pb(NO3)2 + 2KI = PbI2↓+ 2KNO3
Pb2++ 2I ‾ = PbI2↓
2 Pb(NO3)2 2 KI. 0,5 3-4 CH3COOH, 2 , , . ( " ").
2. H2SO4.
SO42+ Pb2+ . . :
PbSO4 + 4KOH = K2[Pb(OH)4] + K2SO4
3. 2CrO4 .
CrO42− PbCrO4, , .
Pb(NO3)2 + K2CrO4 = PbCrO4↓ + 2KNO3
Pb2+ + CrO42− = PbCrO4↓
ճ .
(2-3 ) ᒺ PbCl2 2 . , , . , 1-2 . ³ , .
, , (1-2 ) . , ʲ. Pb2+ , PbCl2.
ϳ , , (1-2 ) NH4OH. Hg22+. Ag+. [Ag(NH3)2]Cl, . AgCl, Ag+.
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1. II ? .
2. II HCl, NH3?
3. Ag+?
4. Pb2+ Ag+, Hg22+?
5. Pb2+ ?
6. 䳿 NH4OH AgCl Hg2Cl2 ? ?
7. Hg22+?
8. HNO3 Ag+?
9. II ?
10.ճ : ) Pb2+ Ag+ ;
) Pb2+ Hg22+;
) Ag+ Hg22+
