AS Level Chemistry Practice Exam 2026 - Free A-Level Chemistry Practice Questions and Study Guide

The hydrolysis of haloalkanes, which involves the reaction of haloalkanes with water to form alcohols, requires the presence of an aqueous alkali catalyst. This condition is essential because the hydroxide ions (OH⁻) provided by the alkali are crucial for facilitating the substitution reaction that replaces the halogen atom in the haloalkane with a hydroxyl group (OH).

In aqueous solution, the hydroxide ions are more nucleophilic than water itself, allowing for a more efficient and rapid reaction. This process typically occurs under mild conditions, making the use of an aqueous alkali catalyst a practical choice for promoting the hydrolysis of haloalkanes.

Other conditions such as the presence of a dry solvent, high pressure, or low temperature are not conducive to the hydrolysis process and do not support the reaction mechanism as effectively as an aqueous alkali would. Thus, the inclusion of an aqueous alkali catalyst is critical for achieving successful hydrolysis of haloalkanes.