Why is it necessary to add excess of mineral acid to diazotise AMINES?

Explanation

During the diazotisation of AMINES', for.one mole of amine, three moles of acid is used.
(i) One mole to dissolve thè amine
(ii) One'mole tọliberate 'HNO_2' from 'NaNO_2, ^prime',
(iii) One mole to maintain the proper acidity of the reaction mixture to prevent the coupling. reaction of the diazonium sa< with the undiazotised (free) amine to form azodye.