MHTCET 20 Apr 2026 Shift 2 Paper

Concept:Phenol is oxidized to $p$-benzoquinone using a strong oxidizing agent.Explanation:The given reaction converts phenol into $p$-benzoquinone.This conversion is an oxidation reaction.Strong oxidizing agents such as $\mathrm{CrO}_3$ or $\mathrm{Na}_2\mathrm{Cr}_2\mathrm{O}_7$/$\mathrm{H}_2\mathrm{SO}_4$ bring about this change.Zinc dust reduces phenol to benzene, so option A is incorrect.$\mathrm{H}_2\mathrm{SO}_4$ at $443\ \mathrm{K}$ causes dehydration, not oxidation, so option B is incorrect.$\mathrm{CS}_2$ at low temperature is used in monohalogenation of phenol, so option C is incorrect.Thus, condition 'A' is oxidation with $\mathrm{CrO}_3$.Answer:Option D — Oxidation with $\mathrm{CrO}_3$.