Question

A mixture of which pair of species react with water to produce a pure colorless gas that gives white fumes with HCl?

• A. Calcium hydride and Calcium carbide
• B. Calcium carbide and aluminium nitride
• C. Magnesium nitride and calcium nitride
• D. Calcium phosphide and calcium cyanamide

Answer 1

Answer: (C)

Magnesium nitride and calcium nitride

$C{a}_3{N}_2+6H_{2}O\to 3Ca(OH{)}_2+2N{H}_3$
$M{g}_3{N}_2+6H_{2}O\to 3Mg(OH{)}_2+2N{H}_3$

$N{H}_3$ gas released in above two reactions give $N{H}_{4}Cl$ white fumes when reacted with $HCl$

$HCl+N{H}_3\to N{H}_{4}Cl$

Hence, option $C$ is correct.