Identify X, Y and Z in the following reactions :
(a) `C_(6)H_(5)NH_(2) underset(HCl)overset(NaNO_(2))rarr X underset(HBr)overset(CuBr)to Y underset("623 K, pressure")to Z`
(b) `C_(6)H_(6) overset(Cl_(2).FeCl_(3))to X overset(CuCN)to Y overset(dil.HCl)to Z`
(c) `C_(6)H_(5)N_(2)^(+)Cl^(-) underset("warm")overset(KI)to X overset(Cu)to Y`

Explanation

(a) `C_(6)H_(5)N_(2)^(+)Cl^(-), C_(6)H_(5)Br, C_(6)H_(5)OH`, (b) `C_(6)H_(5)Cl, C_(6)H_(5)CN, C_(6)H_(5)COOH`
(c) `C_(6)H_(5)I, C_(6)H_(5)-C_(6)H_(5)` (diphenyl)