Question

Give chemical properties with reactions for hydrogen chloride gas.

Answer 1

Chemical properties of hydrogen chloride $\left(\mathrm{HCl}\right)$ gas:

1. Combustibility $\Rightarrow$$\mathrm{HCl}$ is neither combustible nor a supporter of combustion. It does not burn, rather it extinguishes a burning splint.

2. Thermal dissociation $\Rightarrow$ On heating above $500°\mathrm{C}$, it will dissociate into hydrogen and chlorine.

$$\begin{gathered} 2\mathrm{HCl}\left(\mathrm{g}\right)\to {\mathrm{H}}_2\left(\mathrm{g}\right)+{\mathrm{Cl}}_2\left(\mathrm{g}\right) \\ \mathrm{hydrochloric}\mathrm{acid}\mathrm{hydrogen}\mathrm{chlorine} \end{gathered}$$

3. Reaction with metals $\Rightarrow$At high temperature, $\mathrm{HCl}$ gas reacts with metals and liberates hydrogen. Metal such as copper $\left(\mathrm{Cu}\right)$ and silver $\left(\mathrm{Ag}\right)$ also react under these conditions.

$$\begin{gathered} \mathrm{Cu}\left(\mathrm{s}\right)+2\mathrm{HCl}\left(\mathrm{g}\right)\to {\mathrm{CuCl}}_2\left(\mathrm{s}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right) \\ \mathrm{copper}\mathrm{hydrochloric}\mathrm{acid}\mathrm{copper}\mathrm{chloride}\mathrm{hydrogen} \end{gathered}$$

Here, copper is reacting with hydrogen chloride gas, and the product coming is copper chloride and Hydrogen gas.

$$\begin{gathered} 2\mathrm{Na}\left(\mathrm{s}\right)+2\mathrm{HCl}\left(\mathrm{g}\right)\to 2\mathrm{NaCl}\left(\mathrm{s}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right) \\ \mathrm{sodium}\mathrm{hydrochloric}\mathrm{acid}\mathrm{sodium}\mathrm{chloride}\mathrm{hydrogen} \end{gathered}$$

Sodium burns with a golden and yellow flame in dry $\mathrm{HCl}$ gas and forms products of sodium chloride and hydrogen.

4. Reaction with ammonia: When $\mathrm{HCl}$ reacts with ammonia $\left({\mathrm{NH}}_3\right)$, it will form dense white fumes of ammonium chloride which is settled in solid form.

$$\begin{gathered} {\mathrm{NH}}_3\left(\mathrm{g}\right)+\mathrm{HCl}\left(\mathrm{g}\right)\to {\mathrm{NH}}_4\mathrm{Cl}\left(\mathrm{s}\right) \\ \mathrm{ammonium}\mathrm{chloride} \end{gathered}$$