Question

The oxidation number of iron in ${Fe}_3{O}_4$ is:

• A. $+2$
• B. $+3$
• C. $\frac{8}{3}$
• D. $\frac{2}{3}$

Answer 1

Answer: (C)

$\frac{8}{3}$

$F{e}_3{O}_4$ is basically a mixture of $F{e}_2{O}_3$ and $FeO$.

In $F{e}_2{O}_3$, the two $Fe$ atom has $3$ oxidation state.

$2x-6=0$

$x=+3$

In $FeO$, Fe has $2$ oxidation state.

$x-2=0$

$x=2$

Average oxidation state of $Fe=\frac{3+3+2}{3}$

$=\frac{8}{3}$

Hence, option $C$ is correct.