Target Exam

CUET

Subject

Chemistry

Chapter

Organic: Alcohols, Phenols and Ethers

Question:

The conversions which are represented correctly are

Choose the correct answer from the options given below:

Options:

(A), (B) and (D) only

(A), (B) and (C) only

(A), (B), (C) and (D)

(B), (C) and (D) only

Correct Answer:

(B), (C) and (D) only

Explanation:

The correct answer is Option (4) → (B), (C) and (D) only

(A) Phenol to Salicylic Acid (o-Hydroxybenzoic Acid)

  • Intended Product: Salicylic Acid (o-Hydroxybenzoic Acid), which has a –COOH group at the ortho position.
  • Reagents: Chloroform ($CHCl_3$​) and NaOH.
  • Actual Reaction: Phenol with $CHCl_3$​ and NaOH is the Reimer-Tiemann Reaction, which introduces an aldehyde (–CHO) group, yielding Salicylaldehyde (o-Hydroxybenzaldehyde).
  • Conclusion: The reagents shown ($CHCl_3$​, NaOH) do not produce the –COOH group (Salicylic Acid). The correct reagents for Salicylic Acid are $CO_2$​ and NaOH (Kolbe's Reaction). Therefore, conversion (A) is Incorrect.

(B) Phenol to p-Benzoquinone

  • Reaction Type: Oxidation of Phenol.
  • Reagents: Sodium dichromate ($Na_2​Cr_2​O_7$​) in an acidic medium ($H_2​SO_4$​) is a strong oxidizing agent.
  • Product: Phenol is oxidized to p−Benzoquinone. * Conclusion: The conversion of Phenol to p−Benzoquinone using this strong oxidizing agent is Correct.

(C) Phenol to Salicylaldehyde (o-Hydroxybenzaldehyde)

  • Reaction Type: Reimer-Tiemann Reaction.
  • Reagents: Phenol reacts with Chloroform ($CHCl_3$​) in the presence of an aqueous base (NaOH).
  • Product: The reaction introduces an aldehyde (–CHO) group at the ortho position, yielding Salicylaldehyde.
  • Conclusion: The conversion of Phenol to Salicylaldehyde is Correct.

(D) Phenol to Benzene

  • Reaction Type: Reduction of Phenol.
  • Reagents: Phenol is heated (distilled) with Zinc dust (Zn).
  • Product: Zinc reduces the hydroxyl (–OH) group, forming Benzene ($C_6​H_6$​) and Zinc Oxide (ZnO). * Conclusion: The conversion of Phenol to Benzene using Zinc dust is Correct.

Summary

The correct conversions are (B), (C), and (D).