Question

Which of the following is most acidic?

• A. Benzyl alcohol
• B. Cyclohexanol
• C. Phenol
• D. m-Chlorophenol

Answer 1

Answer: (D)

m-Chlorophenol

Answer 2

Halogens have both +R and $- I$ effect, but the –I effect predominates over the +R effect. Therefore, m-Chlorophenol is most acidic due to electron withdrawing –Cl group. Alcohols are less acidic than phenol.