Chemistry - GOC Question with Solution | TestHub

All four are hydroxybiphenyls. In (II) the para nitro group on the second ring withdraws by resonance through the extended π system and stabilises the phenoxide most; in (III) the meta nitro group can withdraw only by induction, so it helps less. (IV) and (I) carry no nitro group, but in (IV) the OH is para to the second ring and the phenoxide charge can delocalise into it, while in (I) the OH is meta and cannot. Hence II $>$ III $>$ IV $>$ I.