, , .
.
:
● (+1);
● (+2);
● (-2);
● (+1).
, ( ), .
, , . . , , . , .
, , , . , , , :
+7 +7 +5 +4
KClO4, KMnO4, NaBiO3, PbO2.
:
;
,
-2 -1 -3
(Na2 S, K I, N H3).
, , 8. , : 5 - 8 = - 3.
, :
, (I2, S, P .);
,
+2 +4 +1
(FeSO4, Na2SO3, NalO).
-
. , , - . , . , .
, H2SO4:
K2Cr2O7 + Na2SO3 + H2SO4 Cr3+ + SO42 -
:
1. :
2K+ + Cr2O72 - + 2Na+ + SO32 - + 2H+ + SO42 - Cr3+ + SO42 -
, .
2. , , :
+6 +4 +6
K2Cr2O7 + Na2SO3 + H2SO4 Cr3+ + SO42 -
|
|
.
3. :
+6
(Cr2O7)2 - Cr3+,
+4 +6
SO32 - SO42 -
4. , :
+6
(Cr 2O7)2 - 2 Cr 3+
+4 +6
S O32 - S O42 -
5. , :
+6
(Cr 2O7)2 - +6 2 Cr 3+,
+4 +6
S O32 - 2 S O42 -.
6. , , + 2, .
: , n , n 2, 2n +:
+6
(Cr2O7)2- +6 +14+ 2Cr3+ + 72;
+4 +6
S O32 - 2 +2 SO42 - + 2+.
7. , ( ), , :
1 | Cr2O72- +6 +14+ 2Cr3+ + 72 | |
SO32- 2 +2 SO42- + 2+ |
8. 1, 3 :
Cr2O72 - + 3SO32 - + 14+ +32 2Cr3+ + 3SO42 - + 6+ + 72
9. ( , , - + 2) :
Cr2O72 - + 3SO32 - + 8+ + 2Cr3+ + 3SO42 - + 42
10. :
K2Cr2O7 + 3Na2SO3 + 4H2SO4 Cr3+ + SO42 -
, Cr3+ SO42 -, 2 Cr3+ 3 SO42 -, 42.
11. (. 1), , . , , , .
, ( 1) Cr2O72 -, Cr3+, SO32 -, SO42 -. Cr3+ SO42 - Cr2(SO4)3 ( 2Cr3+, ( 9)), SO42 - Na+. (8 ) 42, :
K2Cr2O7 + 3Na2SO3+ 4H2SO4 Cr2(SO4)3 + 3Na2SO4 + K2SO4 + 42
12. ( ) .
. - 2 , , +, +!
:
n 2n - ( -), n 2.
|
|
. , , + -. , , - -.
: