How can phenol be obtained from sodium phenoxide?

The correct answer is Option (3) → Acidification

Sodium phenoxide is the salt of the weak acid phenol. A stronger acid, such as dilute \( \ce{HCl} \), gives a proton to the phenoxide ion and sets free phenol:

    \( \displaystyle \ce{C6H5ONa + HCl -> C6H5OH + NaCl} \)

Why the other options are incorrect

Option (1) Oxidation — Incorrect. Going from \( \ce{C6H5O^-} \) to \( \ce{C6H5OH} \) only adds a proton; no electrons are removed, so there is no oxidation.

Option (2) Reduction — Incorrect. No electrons or hydrogen atoms are added to the carbon skeleton; the change is an acid-base reaction, not a reduction.

Option (4) Hydrolysis — Incorrect. Water is a weaker acid than phenol, so water cannot convert the phenoxide ion into phenol; a stronger acid is needed.

NCERT (2026-27 edition):
7.4.2 Preparation of Phenols – “1. From haloarenes
Chlorobenzene is fused with NaOH at 623K and 320 atmospheric pressure. Phenol is obtained by acidification of sodium phenoxide so produced (Unit 6, Class XII).”