Question

4Fe + 3O2 + xH2O → 2Fe2O3 • xH2O

The formation of rust (equation above) is an example of both combustion and

Answer 1

oxidation–reduction (redox) — iron is oxidized (Fe0 → Fe3+) and oxygen is reduced (O2 → O2−) as water participates. Rusting is therefore a redox (corrosion) process as well as combination/combustion.