One mole of magnesium nitride on reaction with an excess of water gives:

Magnesium nitride (${\text{Mg}}_3{\text{N}}_2$) reacts with water to undergo hydrolysis, producing magnesium hydroxide and ammonia.
Reaction: ${\text{Mg}}_3{\text{N}}_2+6{\text{H}}_2\text{O}\to 3\text{Mg}(\text{OH}{)}_2+2{\text{NH}}_3$.
One mole of magnesium nitride yields two moles of ammonia.