How do you prepare an amine from a halogenoalkane?

To prepare an amine from a halogenoalkane, nucleophilic substitution with ammonia is the correct approach. In this reaction, ammonia acts as a nucleophile, attacking the carbon atom of the halogenoalkane that bears the halogen atom. The halogen, being a good leaving group, departs as the ammonia replaces it, resulting in the formation of an amine.

During this process, the nitrogen atom of ammonia, which has a lone pair of electrons, attacks the electrophilic carbon, facilitating the replacement of the halogen. This reaction typically occurs under elevated temperatures and may require a solvent, often an alcohol, to promote the reaction and solubilize the reactants.

The other processes mentioned do not lead to the formation of an amine from a halogenoalkane. Heating with water, for instance, tends to cause hydrolysis rather than substitution, and it primarily leads to the formation of alcohols. Using a soap solution or electrolysis with a base does not directly facilitate the nucleophilic substitution necessary for amine formation and is not a recognized method for synthesizing amines from halogenoalkanes.