Question

A metal X on heating in nitrogen gas gives Y. Y on treatment with $H_{2}O$ gives a colourless gas which when passed through $CuS{O}_4$ solution gives a blue colour. Y is :

• A. $Mg(N{O}_3{)}_2$
• B. $M{g}_3{N}_2$
• C. $N{H}_3$
• D. $MgO$

Answer 1

The correct option is B $M{g}_3{N}_2$

Colorless gas is $N{H}_3$.

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

X Y

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

Ammonia when passed through cooper sulphate forms a deep blue coloured complex.
Option B is correct.