Answer the following questions : (a) (i) Why $ ext{CH}_3 - ext{NH}_2$ is a stronger base than $( ext{CH}_3)_3 ext{N}$ in aqueous solution ? (ii) Write structural formulae of the compound A and B : $\text{CH}_3 ext{CONH}_2 \xrightarrow{\text{NaOBr}} \text{A} \xrightarrow[\text{Base}]{\text{C}_6\text{H}_5\text{COCl}} \text{B}$ (b) A compound 'X' with molecular formula $ ext{C}_3 ext{H}_9 ext{N}$ reacts with Hinsberg reagent to give a product insoluble in alkali. Identify 'X'. OR (b) How can you convert aniline to benzonitrile ? (c) Why is $- ext{NH}_2$ group of aniline acetylated before carrying out nitration ?