Chemistry · Alcohols, Ethers and Phenols

JEE Main 2024 — 27 January, Shift 1 — Question 65

Given below are two statements, one is labelled as Statement I and the other is labelled as Statement II.

Statement (I) : p-nitrophenol is more acidic than m-nitrophenol and o-nitrophenol.

Statement (II) : Ethanol will give immediate turbidity with Lucas reagent.

In the light of the above statements, choose the correct answer from the options given below :

Option A:
Both statement I and statement Il are correct.
Option B:
Statement I is correct and statement Il is incorrect.
Correct
Option C:
Statement I is incorrect and statement Il is correct.
Option D:
Both statement I and statement ll are incorrect.

Answer: B

Step-by-step solution

Statement (I) is correct: In aqueous solution, the acidity order of nitrophenols is $\text{p-nitrophenol} > \text{o-nitrophenol} > \text{m-nitrophenol}$ . p-Nitrophenol is more acidic due to the strong $-R$ (resonance) effect of the $-\mathrm{NO_2}$ group, whereas o-nitrophenol shows intramolecular hydrogen bonding, which reduces solvation of its conjugate base and hence lowers its acidity.

Statement (II) is incorrect: Ethanol is a primary alcohol and does not give immediate turbidity with Lucas reagent at room temperature. Immediate turbidity is observed only with tertiary alcohols.

Therefore, Statement I is correct and Statement II is incorrect → Option B

Answer key and solution verified before publishing.

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Exam: JEE Main 2024
Paper: 27 January, Shift 1
Subject: Chemistry
Chapter: Alcohols, Ethers and Phenols
Topic: Phenols