Question

The acidity of the compounds shown below

follows the order

• A. II > I > III > IV
• B. II > IV > III > I
• C. I > II > IV > III
• D. III > IV > II > I

Answer 1

The Correct Option is B

Compound I (the methyl group attached to a benzene ring with two hydrogen atoms attached to the other carbon atoms) has low acidity due to the electron-donating effects of the methyl group, which stabilize the negative charge on the conjugate base.

Compound II is more acidic because the electron-withdrawing substituent (the –NO₂ group) helps stabilize the negative charge on the conjugate base by delocalizing it.

Compound III has a conjugate base that is stabilized by the aromatic ring, but it is still less acidic than II.

Compound IV is less acidic because the lack of any electron-withdrawing group makes it more difficult to stabilize the negative charge on the conjugate base.

Thus, the order of acidity follows \(II > IV > III > I,\) making (B) the correct answer.