a)
0 0 +3 -1
2Fe + 3Cl2 = 2FeCl3
Fe⁰_-6e-__> 2Fe⁺³ oxidare (ag. red)
3Cl2⁰_+6e-__> 2Cl3⁻ red (ag. ox)
b)
+3 +2 0 +4
Fe2O3 + 3CO = 2Fe + 3CO2
Fe2⁺³_-6e-__> 2Fe⁰ oxid. (ag. red.)
C⁺²_+2e-__> C⁺⁴ red. (ag. ox)
c)
0 0 +1 -1
2Na + Cl2 = 2NaCl
Na⁰_-1e-__> Na⁺ ox (ag red)
Cl2⁰_+2e-_> 2Cl⁻ red (ag. ox)
d)
0 +1 +2 0
Zn + 2HCl = ZnCl2 + H2
Zn⁰_-2e-__> Zn⁺² oxidare (ga. red)
2H⁺_+2e-__> H2⁰ red (ag. ox)
