Give reasons for the following:
(a) Acetylation of aniline reduces its activation effect.
(b) ${\mathrm{CH}}_3{\mathrm{NH}}_2$ is more basic than ${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{NH}}_2$.
(c) Although −NH₂ is o/p directing group, yet aniline on nitration gives a significant amount of m-nitroaniline

(a) On acetylation aniline is converted into acetanilide. The nitrogen lone pair do resonance with carbonyl group. This decreases the activation effect.

(b) lone pair present on N atom of aniline goes into resonance this make it less available for donation and less basic. CH₃NH₂ do not have such delocalized lone pair which make it more basic.

(c) In acidic condition, aniline gets protonated. Due to the protonation of amino group, nitration of aniline gives substantial amount of meta substituted product.