Give reasons :
Although `-NH_(2)` is o/p directing group, yet aniline on nitration gives a significant amount of m-nitroaniline.

Give reasons for the following (a) Acetylation of aniline reduces its activation effect. (b) CH_(3)NH_(2) is more basic than C_(6)H_(5)NH_(2) . (c) Although -NH_(2) is o/p directing group, yet aniline on nitration gives a significant amount of m-nitroaniline.

Account for the following: (i) pK_(b) of aniline is more than that of methylamine. (ii) Ethylamine is soluble in water whereas aniline is not. (iii) Methylamine in water reacts with ferric chloride to precipitate hydrated ferric oxide. (iv) Although amino group is o– and p– directing in aromatic electrophilic substitution reactions, aniline on nitration gives a substantial amount of m-nitroaniline. (v) Aniline does not undergo Friedel-Crafts reaction. (vi) Diazonium salts of aromatic amines are more stable than those of aliphatic amines. (vii) Gabriel phthalimide synthesis is preferred for synthesising primary amines.