The ascending order of acidity of -OH group in the following compounds is : (A) $\mathrm{Bu}-\mathrm{OH}$ (B) (see structure) (C) (see structure) (D) (see structure) (E) (see structure) Choose the correct answer from the options given below :

(D) (A) $<$ (C) $<$ (D) $<$ (B) $<$ (E)

(A) (A) $<$ (D) $<$ (C) $<$ (B) $<$ (E)

(B) (C) $<$ (A) $<$ (D) $<$ (B) $<$ (E)

(C) (C) $<$ (D) $<$ (B) $<$ (A) $<$ (E)

JEE Main · 2024 · 27 Jan 2024 · Shift 1 · Alcohols Phenols and Ethers

The ascending order of acidity of -OH group in the following compounds is :
(A)

Bu - OH

(B) (see structure)
(C) (see structure)
(D) (see structure)
(E) (see structure)

Choose the correct answer from the options given below :

(A)(A) $<$ (D) $<$ (C) $<$ (B) $<$ (E)
(B)(C) $<$ (A) $<$ (D) $<$ (B) $<$ (E)
(C)(C) $<$ (D) $<$ (B) $<$ (A) $<$ (E)
(D)(A) $<$ (C) $<$ (D) $<$ (B) $<$ (E)✓ Correct

Answer: (D)

Solution

Acidity of the

- OH

group tracks how well the conjugate base (the alkoxide/phenoxide) is stabilized. Bu–OH (A), an aliphatic alcohol with no resonance stabilization, is the least acidic. An electron-donating

- OC H_{3}

substituent (C) destabilizes the phenoxide relative to plain phenol (D), so (C) is less acidic than (D). An electron-withdrawing

- N O_{2}

group (B) stabilizes the phenoxide by resonance, making it more acidic than phenol, and two such groups (E) stabilize it further still. The ascending order is

(A) < (C) < (D) < (B) < (E)

JEE Main · 2024 · 27 Jan 2024 · Shift 1 · Single correct option

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JEE Main · 2024 · 27 Jan 2024 · Shift 1 · Alcohols Phenols and Ethers

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