# What is the formula of "magnesium nitride", Mg_3N_2?

Apr 22, 2016

Consider the typical valencies of magnesium metal and dinitrogen in their compounds.

#### Explanation:

Magnesium is a Group 2 metal with 2 valence electrons that can be oxidized:

$M g \rightarrow M {g}^{2 +} + 2 {e}^{-}$

Dinitrogen is a gaseous non-metal that can be reduced to ${N}^{3 -}$: Each nitrogen ATOM has 5 valence electrons, and this configuration can be reduced to ${N}^{3 -}$.

$\frac{1}{2} {N}_{2} \left(g\right) + 3 {e}^{-} \rightarrow {N}^{3 -}$

Since typically non-metals can oxidize metals, or metals reduce non-metals, we cross multiply to give the stoichiometric equation:

$3 M g \left(s\right) + {N}_{2} \left(g\right) \rightarrow M {g}_{3} {N}_{2} \left(s\right)$

Such a reaction is called a nitriding reaction. It would require conditions of high temperature.