. : , , .
. ³ . , , .
, : . .. (1748 .) : , , ( ); - ; , - ; (). . .
, Be At ..뺺, , . 21 H, B, C, N, O, F, Si, P, S, Cl, As, Se, Br, Te, I, - He, Ne, Ar, Kr, Xe, Rn. , . ѳ , i: B, Si, Ge, Sb, As, Te, At. ճ , .
() : ns1-2. ֳ ( 㳿 - ) . , , :
0 - ne = n+
, s - ns1-2 ( H, He), d- f- (d1-10 f1-14) , - 1-2 . , , , . - ( red-ox ) , ( , ) :
<
, , , , , , , , , . , , , 糿.
. - , +, :
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- ne = Me
2 2 + 2e = H + 2-; = -0,41
, , -0,41 ( . ). :
2Na + 2 2 = 2 NaOH + H2
Na0 - 1e = Na+ x2
2H+ + 2x1e = H2 x1
, , . , . Mg, Al, Zn, Cr, Fe
. , , . : Be, Zn, Sn, Pb ( ), Al, Cr,( ).
䳿 :
1.
ZnO + 2NaOH + H2O = Na2[Zn(OH)4 ]
Al2O3 + 6NaOH + 3H2O = 2Na3[ Al(OH)6]
- .
2. (- ) -
Zn + 2H2O = Zn(OH)2 + H2
2Al + 6H2O = 2Al(OH)3 + 3H2
3.
Zn(OH)2 + 2NaOH = Na2[Zn(OH)4 ]
Al(OH)3 + 3NaOH = Na3[ Al(OH)6].
, 䳿 :
Zn + 2NaOH +2H2O = Na2[Zn(OH)4 ] + H2
Zn - 2e = Zn2+ x1
2H2O + 2x1e = H2 + 2OH- x1
2Al(OH)3 + 6NaOH + 6H2O = 2Na3[ Al(OH)6] + 3H2
Al0 - 3e = Al3+ x2
2H2O + 2x1e = H2 + 2OH- x3
, , .
ҳ ( ) . - + , , ()2 ()3:
Zn + 2KOH = K2ZnO2 + H2;
2Al + 6KOH = 2K3AlO3 + 3H2;
(HCl, H SO , H PO , CH COOH), - . - , - , - 0. , red-ox , , :
Fe + H SO = FeSO4 + H2 ; = -0,44 B
2Al + 3H SO = Al2(SO4)3 + 3H2 ; = -1,66 B
Cu + HCl =, = + 0,34 B
, (Pb, Sn,), , , , .
. -, H SO , NO , NO , , - - S , N . , , . ( red-ox , ..). (Li Mg) S; ( Cr) S; (Fe Hg) SO . 䳺 . ³ : NH4NO3, N O; N ; NO. ', , . .
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³ :
Li
H2S + + H2O
+8e Mg
+6e Be
H S+6 O . S + + H2O
Cr
+ 2e Fe
SO2 + + H2O
Hg
, , .
Li
N-3H4N+5O3 + + H2O
+8e 5 2 Mg N2 + + H2O
+4e x2 Be
HN+5 O3. N2O + + H2O
Cr
+3e Fe
SO2 + + H2O
Hg
NO :
1 Mg + HNO3 . 2 NO2 + 1 Mg(NO3)2 + H2O
N+5 +e = N+4 x2
Mg0 - 2e = Mg2+ x1
4 , 4. 4 , 2:
1 Mg + 4 HNO3 . = 2 NO2 + 1 Mg(NO3)2 + 2 H2O
12. .
( ) (Al, Cr, Fe, Co, Ni, Ti, Zr,), , , :
Al + 6 HNO3 . Al2O3 + 6 NO2 + 3 H2O
2Al0 - 3e x2 = Al3+ x1
N+5 + 1e = N+1 x6
18 , .
, - , Hg () . (Au, Pt, .) .