i) Give reason: Aniline is a weaker base than ammonia.
ii) `C_(6)H_(5)NH_(2)overset(NaNO_(2))underset(HCl, 273K)rarr X overset(Cu_(2)Cl_(2))underset(HCl)rarr Y`. 

Explanation

b) i) Lone pair of electrons density on nitrogen less available in aniline due to delocalization so aniline is weaker base than ammonia.
ii) Aromatic primary amines react with `NaNO_(2) & HCl` at low temperature `(273 - 278 K)` to form diazonium salt. This reaction is called diazotisation. Freshly prepared diazonium salt is treated with cuprous chloride or cuprous bromide to give aryl
chloride or aryl bromide this reaction is called sandmeyer.s reaction.