The reactions of amines are mainly due to participation of unshared pair of electrons of nitrogen which makes them react as a nucleophile or a base (A nucleophile is a species that attacks an electron - deficient carbon and a base is a species that attacks an electron deficient hydrogen i.e., proton)Salt formation
In aromatic amines, the unshared pair of electrons on the N atom facilitates electrophilic substitution in the phenyl ring. The number of hydrogen atoms on the amine ring also effect the reactions.
Amines being basic react with acids to form salts.
Salts of amines are typical ionic solids. Amine salts are soluble in water but insoluble in non-polar solvents. The aqueous solutions of these amines on treatment with aqueous hydroxide regenerate the amines.