Primary nitro compounds react with $HNO_2$ to form crystalline solids which,on treatment with $NaOH$,give:

When aniline is treated with sodium nitrite and hydrochloric acid at $0\,^{\circ}C$,it gives:

Which from the following amines has the highest $pK_{b}$ value?

What is the physical state of pure aniline?

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.

What is the product formed when benzene diazonium chloride reacts with ethanol?