JAMB Chemistry 2024 Paper

Concept:In preparing ethanoic acid, a non-volatile acid is preferred so that it stays in the reaction vessel during heating.Hydrochloric acid is unsuitable mainly because it is too volatile.Explanation:Ethanoic acid ($\mathrm{CH_3COOH}$) is often produced in the laboratory by the oxidation of ethanol under heat.A suitable acid, such as sulphuric acid ($\mathrm{H_2SO_4}$), should remain in the mixture throughout the reaction to provide the acidic medium.Hydrochloric acid ($\mathrm{HCl}$) has a low boiling point and is easily evaporated.When the mixture is heated, $\mathrm{HCl}$ escapes as a gas before the alcohol can be properly oxidized to ethanoic acid.This volatility is the key reason $\mathrm{HCl}$ is not suitable.Its unsuitability is not because of its acidic strength, its action on cork and rubber, or its effect on litmus paper.Answer:$\mathrm{B}$ — Hydrochloric acid is not suitable because it is too volatile.