Question

Alkyl halide react with ammonia

Answer 1

The reaction happens in two stages. In the first stage, a salt is formed - in this case, ethylammonium bromide. This is just like ammonium bromide, except that one of the hydrogens in the ammonium ion is replaced by an ethyl group.

CH3CH2Br+NH3→CH3CH2NH+3+Br−CH3CH2Br+NH3→CH3CH2NH3++Br−

There is then the possibility of a reversible reaction between this salt and excess ammonia in the mixture.

CH3CH2NH+3+NH3⇌CH3CH2NH2+NH+4Br−CH3CH2NH3++NH3⇌CH3CH2NH2+NH4+Br−

The ammonia removes a hydrogen ion from the ethylammonium ion to leave a primary amine - ethylamine. The more ammonia there is in the mixture, the more the forward reaction is favored.

Answer 2

Ammonia reacts as a nucleophile with alkyl halides to give primary amines in a nucleophilic substitution reaction.