Identify the major product formed in the following reaction:

Step-by-step solution

The given reaction is the Elbs persulfate oxidation. When phenol is treated with potassium persulfate ( K₂S₂O₈ ) in an alkaline medium ( HO^- / H₂O ), it undergoes oxidation to form a dihydric phenol. The persulfate ion attacks the phenoxide ion primarily at the para position to form an intermediate sulfate ester. Upon hydrolysis, this intermediate yields hydroquinone (benzene-1,4-diol) as the major product. If the para position is blocked, the ortho product is formed. Since the para position in phenol is unsubstit