Question

Consider this reaction: Fe2O3 + S Right arrow. Fe + SO2
Reduction half-reaction: 2Fe+3 + 6e- Right arrow. 2Fe
Oxidation half-reaction: S Right arrow. S+4 +4e-

After balancing the chemical equation, what are the coefficients for these compounds?

Fe

SO2

Answer 1

Balance the electrons: multiply the reduction (6 e-) by 2 and the oxidation (4 e-) by 3 to get 12 e-.

That gives 4 Fe3+ + 3 S → 4 Fe + 3 S4+.

Each Fe2O3 supplies 2 Fe3+ and 3 O, so 2 Fe2O3 + 3 S → 4 Fe + 3 SO2.

Coefficients:
- Fe: 4
- SO2: 3