Question

Complete the reaction.

${\mathrm{NCl}}_3\stackrel{\mathrm{B}}{\leftarrow }$${\mathrm{NH}}_3\stackrel{\mathrm{A}}{\to }$ ${\mathrm{NH}}_4\mathrm{Cl}$

Answer 1

Chemical properties of Ammonia:

Reaction with acids: As Ammonia is a base, it reacts with acids to form Ammonium salts.

Example: Ammonia (${\mathrm{NH}}_3$) reacts with Hydrochloric acid $\left(\mathrm{HCl}\right)$ to form Ammonium chloride salt$\left({\mathrm{NH}}_4\mathrm{Cl}\right)$.

${\mathrm{NH}}_3\left(\mathrm{g}\right)+\mathrm{HCl}\left(\mathrm{g}\right)\to {\mathrm{NH}}_4\mathrm{Cl}\left(\mathrm{s}\right)$

So two colorless gases Ammonia and Hydrochloric acid react to give solid Ammonium chloride.

Chemical properties of ammonia:

Reducing agent: Reducing agent reduces the other substance by adding hydrogen to it.

Example: Ammonia on reaction with an excess of Chlorine reduces chlorine to hydrogen chloride.

$$\begin{gathered} {\mathrm{NH}}_3\left(\mathrm{g}\right)+3{\mathrm{Cl}}_2\left(\mathrm{g}\right)\to 3\mathrm{HCl}\left(\mathrm{l}\right)+{\mathrm{NCl}}_3\left(\mathrm{l}\right) \\ \mathrm{excess}\mathrm{explosive} \end{gathered}$$

So Ammonia acts as a reducing agent and reduces chlorine to Hydrogen chloride and a by product Nitrogen trichloride$\left({\mathrm{NCl}}_3\right)$ is formed in excess of chlorine.