Question

A piece of magnesium ribbon was heated to redness in nitrogen gas and then dropped into water. The gas evolved is:

• A. $N{H}_3$
• B. $H_2$
• C. $O_2$
• D. $N_2$

Answer 1

The correct option is A $N{H}_3$

When heated to redness in presence of air, magnesium reacts with nitrogen to form magnesium nitride.

$3Mg+N_2\to M{g}_3{N}_2$

Magnesium nitride reacts with water to form ammonia.

$M{g}_3{N}_2+3H_{2}O\to 2N{H}_3+3MgO$