Question 18 of 39beginner🧠 RememberShort Answer2 marks

Write chemical reaction for the preparation of phenol from chlorobenzene.

Correct Answer

Phenol can be prepared from chlorobenzene by fusing it with NaOH at 623 K and 320 atmospheric pressure. Sodium phenoxide is formed, which is then acidified to obtain phenol.

Reaction:

Cl+NaOH→623 KONa+HCl\text{Cl} + \text{NaOH} \xrightarrow{623 \text{ K}} \text{ONa} + \text{HCl}

The sodium phenoxide so produced is acidified to yield phenol.

Exercise: EXERCISES | Q: 7.10 | (Page Page 30)
For More Understanding

Explanation

The textbook context explicitly mentions under 'From haloarenes' that chlorobenzene is fused with NaOH at 623K and 320 atmospheric pressure to form sodium phenoxide, which upon acidification gives phenol. This is a nucleophilic aromatic substitution reaction where the -Cl group is replaced by -OH group. The high temperature and pressure conditions are necessary because the C-Cl bond in chlorobenzene is strong due to partial double bond character (resonance).

Solution Steps

  1. Step 1: Chlorobenzene is fused with NaOH at 623K and 320 atm pressure to form sodium phenoxide.

  2. Step 2: Sodium phenoxide is acidified to obtain phenol.

PreviousNext