Question

Why Ammonia cannot be obtained in laboratory from Ammonium nitrate and Sodium hydroxide?

Answer 1

Preparation of Ammonia gas:

Preparation of ammonia from Ammonium salts: Ammonia gas is obtained by treating Ammonium salt with Calcium hydroxide.

Ammonium salt + alkali $\stackrel{∆}{\to }$ Metal salt + water + Ammonia gas

Decomposition of Ammonium nitrate:

Some compounds of Ammonia like Ammonium nitrate$\left({\mathrm{NH}}_4{\mathrm{NO}}_3\right)$ which on warming with alkali like Sodium hydroxide $\left(\mathrm{NaoH}\right)$ do not produce Ammonia, because these compounds are highly unstable and decompose by heating only.

${\mathrm{NH}}_4{\mathrm{NO}}_3\left(\mathrm{s}\right)\stackrel{∆}{\to }$${\mathrm{N}}_2\mathrm{O}\left(\mathrm{g}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$

Ammonium nitrate Nitrous oxide water

Because of unstable nature of Ammonium nitrate, it cannot produce Ammonia.