Cu2+, Co2+, Ni2+, Cd2+, Hg2+.
: Cu2+ − [Ar]3d9; Co2+ − [Ar]3d7; Ni2+ − [Ar]3d8; Cd2+ − [Kr]4d10; Hg2+ − [Xe]4f145d10.
, , .
, ,
[Co(CN)6]3 =11064; | [Cd(CN)4]2 =1,761018; |
[Ni(CN)4]2 =11031; | [Cu(NH3)4]2+ =9,331013; |
[Ni(NH3)6]2+ =1,23108; | [Hg(CN)4]2 =3,091042; |
[Hg(SCN)4]2 =1,71020 |
(w=25%) . ó Cu2+, Ni2+, Co2+ , . Cd2+, Hg2+ .
䳿 NaOH, KOH , Cu2+, Ni2+, Cd2+, :
Cu2+ + 2− → u(OH)2↓ ;
Ni2+ + 2− → Ni(OH)2↓ - ;
Cd2+ + 2−→ d(OH)2↓ .
Hg2+- HgO, Co2+ 䳿 :
Hg2+ + 2− → HgO↓ + 2;
Co2+ + − + l− ( ) → Co(OH)Cl↓.
(HCl, HNO3, H2SO4), , Hg, (w=25%) .
, , :
2Cu2+ + SO42 + 2NH3H2O→ u2(OH)2SO4↓ + 2NH4+;
Cd2+ + 2NH3H2O → d(OH)2↓ + 2NH4+;
HgCl2 + 2NH3H2O → [NH2Hg]Cl↓ + NH4+ + Cl− + 22;
NiCl2 + NH3H2O → Ni(OH)Cl↓ + NH4+ + Cl−;
CoCl2 + NH3H2O → Co(OH)Cl↓ + NH4+ + Cl−.
䳿 :
Cu2+ + 4NH3H2O → [u(NH3)4]2+ + 42
-;
Ni2+ + 6NH3H2O → [Ni(NH3)6]2+ + 62 ;
Co2+ + 6NH3H2O → [Co(NH3)6]2+ + 62 ;
Cd2+ + 4NH3H2O → [d(NH3)4]2+ + 42 ;
Hg2+ + 4NH3H2O → [Hg(NH3)4]2+ + 42 ;
Ni2+ + 6NH3H2O → [Ni(NH3)6]2+ + 62 -.
NH4Cl.
[Co(NH3)6]2+ 䳺 , 䳺 , [Co(NH3)6]3+, - .
- :
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Cu2+ + S2 → uS↓;
Ni2+ + S2− → NiS↓;
Co2+ + S2− → CoS↓;
Hg2+ + S2− → HgS↓;
Cd2+ + S2− → dS↓ ..
(uS)=6,31046; (HgS)=1,61052; (NiS)=3,21019;
(dS)=1,61028; (β-S)=1,91027.
CoS NiS . CdS , CuS − , . HgS , .
Na2S H2S. , H2S , Na2S .
4.7.1. Cu2+
1. 䳿 Cu2+ , - :
u2+ + 2NH3H2O → Cu(OH)2↓ + 2NH4+;
Cu(OH)2 + 4NH3H2O → [u(NH3)4](OH)2 + 4H2O.
2. ³ u2+ u+ . u2+ , Cd2+, Hg2+.
, u2+, Na2S2O3 . - Cu2S.
u2+ .
Na2S2O3:
2CuSO4 + 2Na2S2O3 → Na2SO4 + Na2S4O6 + Cu2SO4; Cu2SO4 + Na2S2O3 → Na2SO4 + Cu2S2O3; Cu2S2O3 + Na2S2O3 → Na2[Cu2(S2O3)2]; Na2[Cu2(S2O3)2] + H2SO4 → Na2SO4 + H2[Cu2(S2O3)2]; H2[Cu2(S2O3)2] → H2SO4 + SO2↑ + S↓ + Cu2S↓. |
ϳ :
2CuSO4 + 4Na2S2O3 → 3Na2SO4 + Na2S4O6 + SO2↑ + S↓ + Cu2S↓.
:
CuSO4 + Na2S2O3 → CuS2O3 + Na2SO4;
CuS2O3 + H2O →CuS ↓+ H2SO4.
Cu2+, Cd2+, Hg2+ , Cd2+ . () , () . , Cu2+, () , Cu2S S.
Cu2+ Cu+ , , :
Na2S2O3 + 2HNO3 → Na2SO4 + 2NO2↑ + S + H2O.
3. , , Cu2+ .
, =1−2. :
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Cu2+ + Zn → Cu + Zn2+.
, Cu2+ Cu . Cu2+:
Zn + 4HNO3 → Zn(NO3)2 + 2NO2↑ + 2H2O.
4. Cu2+ K4[Fe(CN)6]:
2Cu2+ + [Fe(CN)6]4 → u2[Fe(CN)6]↓.
- . , u2[Fe(CN)6] 䳺 . Fe3+ Fe4[Fe(CN)6]3 .
Fe3+, , , , Fe3+ . , , [FeF6]3.
Cu2+ [Fe(CN)6]3 Fe3+, 3-4 NaF, 2-3 CH3COONa, 1-2 4[Fe(CN)6]. - Cu2+. , .
4[Fe(CN)6] , , u2[Fe(CN)6]: d2[Fe(CN)6] Hg2[Fe(CN)6] ; 2[Fe(CN)6] - ; Ni2[Fe(CN)6] - .
Cu2+ 4[Fe(CN)6] .
5. 䳿 Cu2+ - CuI :
Cu2+ + 2I− → CuI2;
2uI2 → 2CuI↓ + I2.
(, ), .
6. 䳿 Cu2+ :
.
7. () Cu2+ - Cu[Hg(SCN)4]Zn[Hg(SCN)4].
C2+, (NH4)2[Hg(SCN)4] - [Hg(SCN)4] Zn2+ C[Hg(SCN)4]Zn[Hg(SCN)4] - . Cd2+ d[Hg(SCN)4]. Fe3+, , Cu[Hg(SCN)4].
4.7.2. C2+
ó C2+ - .
1. C2+ - [(SCN)4]2:
C2+ + 4SCN → [(SCN)4]2.
() - . ³ , . () (NH4)2[(SCN)4] , . , . - :
[(SCN)4]2 Co2+ + 4SCN.
, Co2+, 8-10 , 5-6 . ϳ , Co2+.
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Co2+ - Cu2+, Fe3+, Bi3+, - .
Co2+ , , . , NH4SCN KSCN, . , , . . Co2+, .
2. 䳿 C2+ () (NH4)2[Hg(SCN)4] C[Hg(SCN)4]. Zn2+ :
2(NH4)2[Hg(SCN)4] + Zn2+ + C2+ → C[Hg(SCN)4]Zn[Hg(SCN)4]↓ + 4NH4+.
2+ Cu2+, Fe3+, Ni2+ , .
2-3 (NH4)2[Hg(SCN)4], 2 (( H2SO4)=2,0/3), 2 ZnSO4 2 2+ . . .
3. C2+ KNO2.
, KNO2 (w=20%), . C2+ 3+ K3[Co(NO2)6]:
C2+ + 7KNO2 + 23 → K3[Co(NO2)6]↓ + NO↑ + H2O + 2CH3COO + 4K+
C3+:
C3+ + 6KNO2 → K3[Co(NO2)6]↓ + 3K+.
C3+ ; C2+ . C2+ C3+ H2O2 .
C2+ K3[Co(NO2)6] 20-30 .
C2+ C3+ Ni2+ Ca2+, Sr2+, Ba2+, Pb2+, 2[Ni(NO2)6], Ca2+, Sr2+, Ba2+, Pb2+.
4. Co2+- -R- ( 3--4--2,7-).
2+ 3+. 3+- -R- ≈5,5 , :
4.7.3. Ni2+
ó Ni2+ .
1. Ni2+ ( ) . , - :
Ni2+ + 6NH32O → [Ni(NH3)6]2+ + 6H2O;
ͳ, 1-2 22 Fe2+ Fe3+ 5-6 . , . . - .
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9.
Fe2+, Cu2+, Co2+, Ni2+ . Cu2+ Co2+, , , .
Ni2+ , , .
Cu2+ , , . Cu(OH)2, () , . , - . Ni(OH)2 Cd(OH)2 [Ni(NH3)4]2+ [Cd(NH3)4]2+, uO .
, Cu2+ Hg2+ uS HgS.
Fe2+ , , Fe3+ 22. Fe3+ .
2. Ni2+ 4[Fe(CN)6] Ni2[Fe(CN)6]:
2Ni2+ + [Fe(CN)6]4 → Ni2[Fe(CN)6]↓.
3. Na2HPO4 Ni2+ :
3Ni2+ + 2HPO42 → Ni3(PO4)2↓ + 2+.
4. NH4SCN Ni2+ - , :
Ni2+ + 2SCN → Ni(SCN)2↓.
Ni(SCN)2 + 2NH4SCN → [Ni(SCN)4]2 + 2NH4+.
4.7.4. Hg2+
.
1. 䳿 Hg2+ () , :
Hg2+ + H2S → HgS↓ + 2H+.
() :
HgS + Na2S → Na2HgS2↓,
:
3HgS + 6HCl + 2HNO3 → 3HgCl2 + 2NO↑ + 3S↓ + 4H2O.
HgCl2 .
HgS 䳿 Hg2+ :
Hg2+ + S232 → HgS↓ + SO32.
2. 䳿 Hg2+ - () :
Hg2+ + 2 → Hg2↓,
:
Hg2 + 2ʲ → 2[Hg4]; [Hg4]2 = 51031.
Hg2+ , Ag+ Pb2+, . , , . AgCl PbSO4.
Hg2+ - <6.
, [Hg4]2 = 51031, (Hg2)=6,81013, Hg2+ 䳿 KI Hg2 , () [Hg4]2.
, Hg2+ . , ʲ. :
Hg2+ + 2 → Hg2;
Hg2 + 2ʲ → 2[Hg4].
. 2[Hg4] . ϳ , , . .
3. Hg2+ Sn2+-:
2HgCl2 + SnCl2 → Hg2Cl2↓ + SnCl4;
Hg2Cl2 + SnCl2 → 2Hg↓ + SnCl4.
SnCl2 . <5.
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Sn2+ SnIV.
4. ³ Hg2+ .
Hg2+ . :
Hg2+ + u → Hg↓ + Cu2+.
Hg2+ Ag+, Bi3+, [Hg2]2+, Sb3+, .
Sb3+ Bi3+ .
5. ̳ Hg2+.
, Hg2+, . Co(NO3)2 NH4SCN. [Hg(SCN)4] , , . ֳ .
. Co[Hg(SCN)4]
6. Hg2+ .
, , 쒿 . . ϳ , , , -1 -3. , , Hg2+ 쒿 . ϳ . Hg2+ .
7. Hg2+ .
. Hg2+ - :
4.7.5. Cd2+
1. ó H2S Cd2+ CdS:
Cd2+ + H2S → dS↓ + 2H+.
Cd2+ , .
, , .
3-4 , Cd2+, 6 , 2-3 Na2S2O3 . HgS Cu2S. Co2+, Ni2+, Cd2+. . 5-6 H2S 2-3 . CdS, .
, -.
2. ҳ :
.
, 䳿 H2S, [Cd(CSN2H4)3]2+=1,2103, (CdS)=3.61029. :
[Cd(CSN2H4)3]2+ + H2S → CdS↓ + 3CSN2H4 + 2+.
.
3-4 Cd2+- , 3-4 , , 2-3., 5-6 H2S. - . Cd2+ Cu2+, .
3. Cd2+ ʲ:
Cd2+ + 4NH3H2O + 2I → [Cd(NH3)4]2↓ + 4H2O.
Cd2+ ʲ NH3H2O .
, Cd2+, Cd(OH)2, ʲ (w=40%). [Cd(NH3)4]2.
Cd2+ , , , ʲ , [Cd(NH3)4]()2. Cd2+ , .