(i) On reduction in neutral media, using Zn dust and NH4Cl solution nitrobenzene gives phenyl hydroxylamine.
(ii) While in alkaline medium, using Zn−NaOH, mononuclear intermediate products (nitrobenzene and phenylhydroxyl amine) interact to each other to give dinuclear product. Final product using Zn−NaOH is hydrazobenzene, which in a formed viz the formation of azoxybenzene and azobenzene.