Question

A substance A is heated with slaked lime and a gas B with a pungent smell is obtained. Name substances A and B, and give the balanced equation.

Answer 1

Reaction of ammonium chloride $\left({\mathrm{NH}}_4\mathrm{Cl}\right)$ with slaked lime $\left(\mathrm{CaO}\right)$:

• Ammonia $\left({\mathrm{NH}}_3\right)$ is synthesized in the laboratory by heating a combination of ammonium chloride and dry slaked lime (calcium hydroxide).
• $2{\mathrm{NH}}_4\mathrm{Cl}\left(\mathrm{aq}\right)+\mathrm{Ca}\left(\mathrm{OH}{)}_2\left(\mathrm{aq}\right)\stackrel{\text{Heat}}{⟶}{\mathrm{CaCl}}_2\right(\mathrm{aq})+2{\mathrm{H}}_2\mathrm{O}(\mathrm{l})+2{\mathrm{NH}}_3(\mathrm{aq})\uparrow$
• Here, the ammonia gas released is of pungent smell.

Therefore, substance A heated with slaked lime would be ammonium chloride and gas B with a pungent smell would be ammonia gas.