COMEDK2024ChemistryAlcohols Phenols and EthersActual
Arrange the following compounds in the decreasing order of their acidic strength. (I) m-cresol (II) Phenol (III) m-aminophenol (IV) m-methoxyphenol
Options
- AI > II > III > IV
- BIV > III > II > I
- CI > III > IV > II
- DIII > I > II > IV
Correct answer
B. IV > III > II > I
Step-by-step solution
At meta position, only inductive effect (I-effect) operates, not resonance. m-methoxyphenol: -OCH₃ has strong -I effect (O is highly electronegative) stabilizes phenoxide most acidic. m-aminophenol: -NH₂ has -I effect but weaker than -OCH₃ (N less electronegative than O) more acidic than phenol. Phenol: reference compound, no substituent. m-cresol: -CH₃ has +I effect destabilizes phenoxide least acidic. Decreasing order: IV > III > II > I