1. CuO + H1
2S6 O-2
4--------------Cu2 S6 O-2
4 + H1
2 O-2 + S4 O-2
2
Cu0 +2 e-------------- Cu2
S6 -2e-------------- S4
2(Cu0 +2 e-------------- Cu2 ) = 2Cu0 +4e-------------- 2Cu2
2(S6 -2e-------------- S4 ) = 2S6 -4e-------------- 2S4
Cu + 2H2SO4--------------CuSO4 +2 H2O + SO2
1-Cu-1
2-S-2
8-O-8
4-H-4

2.  Mg 1
 Cu = 63 x1
 63 g/m
 Mg 2
 H= 1 x 4 = 4
 S= 32 x 2 = 64
 O=16 x 8 = 128
 196 m/g
 Mg3
 Cu= 63 x1 =63
 S= 32 x1= 32
 O= 16 x 4= 64
 =159 m/g
 Mg4
 H= 1x4= 4
 O= 16 x 2= 32
 =36 m/g
Mg 5
S =32 x 1 = 32
O= 16 x 2 = 32
=64 m/g

3. Fe3
2 O-2
3 + C2 O-2 ------------ Fe0 + C4 O-2
2
Fe3 -3e- ------------ Fe0
C2+2e ------------ C4
2(Fe3 -3e- ------------ Fe0 ) = 2Fe3 -6e- ------------ 2Fe0
3(C2+2e ------------ C4 ) = 3C2+6e ------------ 3C4
Fe2 O3 + 3CO ------------ 2Fe +3CO2
2-Fe-2
6-O-6
3-C-3

4.  Mg 1
 Fe= 56 x 2 =112
 O = 16 x 3 =48
 = 160 m/g
 Mg 2
 C = 12 x 3 = 36
 O= 16 x 3 =48
 =84 m/g
 Mg 3
 Fe= 56 x 2= 112
 =122 m/g
 Mg 4
 C =12 x 3 = 36
 O=16 x 6 = 96
 =132 m/g