Chemistry - Complete s-block Question with Solution | TestHub

The given reaction is $3\mathrm{Mg}+{\mathrm{N}}_2⟶{\mathrm{Mg}}_3{\mathrm{N}}_2$.

The oxidation state of elemental Mg is $0$.

In ${\mathrm{Mg}}_3{\mathrm{N}}_2$, the oxidation state of Mg is $+2$.

Since the oxidation state of Mg increases from $0$ to $+2$, Mg undergoes oxidation.

The oxidation state of elemental ${\mathrm{N}}_2$ is $0$.

In ${\mathrm{Mg}}_3{\mathrm{N}}_2$, the oxidation state of N is $-3$.

Since the oxidation state of N decreases from $0$ to $-3$, ${\mathrm{N}}_2$ undergoes reduction.

Thus, Mg is oxidised.

Answer: Mg is oxidised