Diazonium Salt

When an primary aromatic amine is treated with NaNO_(2)+HCI at 0^(@)-5^(@)C , a diazonium salt is formed and the reaction is called diazo reaction. In this reaction mineral acid must be added to prevent the coulping reaction of diazonium salt with excess of aryl amine. diazonium salt is highly in the synthesis of number of coloured dyes. For the following diazonium ion the decreasing order of reactivity of these ion in azo-coupling reaction:

(a) Write the reactions involved in the following : (i) Hofmann bromamide degradation reaction. (ii) Diazotisation . (iii) Gabriel phthalimide synthesis (b) Give reasons : (i) (CH_(3))_(2)NH is more basic than (CH_(3))_(3)N in an aqueous solution. (ii) Aromatic diazonium salts are more stable than aliphatic diazonium salts .