Question

For the preparation of hydrochloric acid in the laboratory: Why is direct absorption of hydrogen chloride gas in water not feasible?

Answer 1

• The direct absorption of hydrogen chloride gas in water is not feasible because Hydrogen chloride gas is soluble in water and also this reaction is highly exothermic.
• When Hydrogen chloride is dissolved in water and produces hydronium ions and Chlorine ions.

$\underset{\mathrm{Hydrochloric}\mathrm{acid}}{\mathrm{HCl}\left(\mathrm{g}\right)}+\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}\to \underset{\mathrm{Hydronium}\mathrm{ion}}{{\mathrm{H}}_3{\mathrm{O}}^{+}\left(\mathrm{aq}\right)}+\underset{\mathrm{Chlorine}\mathrm{ion}}{{\mathrm{Cl}}^{-}\left(\mathrm{aq}\right)}$

• Hydrogen chloride can easily dissociate into consisting ions within an aqueous medium.

Hence, For the preparation of hydrochloric acid in the laboratory, direct absorption of hydrogen chloride gas in water is not feasible because Hydrogen chloride $\left(\mathrm{HCl}\right)$gas is soluble in water.