Question

The ${\text{N}}{{\text{H}}_{\text{4}}}{\text{Cl}}$ , ${\text{N}}{{\text{H}}_{\text{4}}}{\text{N}}{{\text{O}}_{\text{3}}}$ , ${\left( {{\text{N}}{{\text{H}}_{\text{4}}}} \right)_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}}$ give ${\text{N}}{{\text{H}}_3}$ gas on heating.
A.True
B.False

Answer 1

The salts of ammonium generally release ammonia gas when heated but not all of them release ammonia, certain other gases are released as well. The gas which doesn’t release ammonia is a nitrate.

Complete answer:
When the ammonium salts are heated then they give up ammonia gas and along with that certain other products are also formed. When ammonium chloride is heated then it form ammonia gas and hydrogen chloride gas. This is because ammonium chloride is made from the ammonium cation and the chloride anion in which the ammonium cation is formed when the hydrogen atom from hydrogen chloride accepts the lone pair of electron from the nitrogen atom of ammonia by a coordinate covalent bond. Hence, due to heating the lattice breaks down and the ammonia gas is released.
But when ammonium nitrate is heated, then nitrous oxide and water vapour are formed while ammonium carbonate on heating releases ammonia gas, carbon dioxide , and water vapour.
Hence, the correct answer is: ammonium chloride and ammonium carbonate release ammonia gas on heating but ammonium nitrate does not. The reactions of the heating of the above salts are as follows:
${\text{N}}{{\text{H}}_{\text{4}}}{\text{Cl }}\xrightarrow{\Delta }{\text{ N}}{{\text{H}}_{\text{3}}}{\text{ + HCl}}$
${\text{N}}{{\text{H}}_{\text{4}}}{\text{N}}{{\text{O}}_{\text{3}}}\xrightarrow{\Delta }{{\text{N}}_{\text{2}}}{\text{O + }}{{\text{H}}_{\text{2}}}{\text{O}}$
${\left( {{\text{N}}{{\text{H}}_{\text{4}}}} \right)_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}}\xrightarrow{\Delta }{\text{ 2N}}{{\text{H}}_{\text{3}}}{\text{ + C}}{{\text{O}}_{\text{2}}}{\text{ + }}{{\text{H}}_{\text{2}}}{\text{O}}$

Note:
The formation of ammonium chloride from ammonia and hydrogen chloride is used for the identification of either hydrogen chloride gas or ammonia gas. The formation of white fumes of ammonium chloride is the proof that the gas is either of the gas mentioned earlier. The fumes are formed because ammonium chloride is sublimable and converts directly into gas from the solid state.