Question

The oxidation number of $Fe$ in Magnetite $\left({Fe}_3{O}_4\right)$ is:

Answer 1

1) $F{e}_3{O}_4$ contains Fe atoms of both $+2$ and $+3$ oxidation number.

2) It is a stoichiometric mixture of Ferrous $\left(FeO\right)$ and Ferric $\left(F{e}_2{O}_3\right)$oxides combined as $FeO.F{e}_2{O}_3$.

3) Therefore, the oxidation number found in such cases is average oxidation number.