Write the reactions of $(i)$ aromatic and $(ii)$ aliphatic primary amines with nitrous acid.

The correct order of base strength in benzene as a solvent for the given amines is:
$I: CH_3CH_2NH_2$
$II: (CH_3CH_2)_2NH$
$III: (CH_3CH_2)_3N$

In the reaction $C_6H_5CHO + C_6H_5NH_2 \to C_6H_5N=CHC_6H_5 + H_2O$,the compound $C_6H_5N=CHC_6H_5$ is known as

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.

Which of the following compounds is $NOT$ formed as an intermediate product in the Hofmann bromamide degradation reaction?

Aniline under acidic medium,when chlorinated,produces :