# help with chemistry half reactions?

1. 4Fe + 3O2 → 2Fe2O3

2. 2Al + 3CuCl2 → 3Cu + 2AlCl3

3, 8Cu + S8 → 8CuS

Thanks

### 1 Answer

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- Lexi RLv 78 years agoFavorite Answer
1.

The oxidation state of Fe is 0 in the LHS and 3+ on the RHS. So it is losing 3 electrons.

Oxidation is loss, so this is the oxidation half equation

Fe ----> Fe^3+ + 3e

The oxidation state of O on The LHS is 0. On the RHS it is 2-. So it is gaining 2 electrons.

Reduction is gain, so this is the reduction half equation

O2 + 4e -----> 2O^2-

2.

Al on LHS = 0, on RHS = 3+

Al ----> Al^3+ + 3e

Cu on LHS = 2+, on RHS = 0

Cu^2+ + 2e ---> Cu

3.

Cu on LHS = 0, on RHS = Cu^2+

Cu ----> Cu^2+ + 2e

S on LHS = 0, on RHS = 2-

S8 + 16e ----> 8S^2-

Those are the balanced half equations (they don't include the balancing required when you add the two half equations together)

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