Compound 'P' is formed by the oxidation of cumene followed by acidic hydrolysis. 'P' undergoes three separate reactions as follows: (i) 'P' reacts with Reagent I to give p -benzoquinone. (ii) 'P' reacts with Reagent II to give a white precipitate of 2,4,6-tribromophenol. (iii) 'P' reacts with Reagent III to give p -bromophenol as the major product. Identify Reagent I, Reagent II, and Reagent III.

Step-by-step solution

The oxidation of cumene followed by acidic hydrolysis is the commercial method for the preparation of phenol. Thus, compound 'P' is phenol. Reaction (i): Phenol undergoes oxidation with a strong oxidizing agent like acidified sodium dichromate ( Na ₂ Cr ₂ O ₇ / H ₂ SO ₄ ) to produce a conjugated diketone known as p -benzoquinone. Hence, Reagent I is Na ₂ Cr ₂ O ₇ / H ₂ SO ₄ . Reaction (ii): When phenol is treated with bromine water ( Br ₂ in a polar solvent like H ₂ O ), the highly activating nature of the - OH gro