MHT CET202618 April 2026Evening ShiftChemistryAlcohols Phenols and EthersActual
Select the correct decreasing order of acid strength for the following compounds. a) Ethanol b) 2-Methyl propan-2-ol c) Phenol d) p - Nitrophenol
Options
- Aa > b > c > d
- Bc > d > b > a
- Cd > c > a > b
- Dd > b > c > a
Correct answer
C. d > c > a > b
Step-by-step solution
Acid strength is directly proportional to the stability of the conjugate base formed after the removal of an H^+ ion. The conjugate bases are: a) Ethoxide ion ( CH₃CH₂O^- ) b) tert-Butoxide ion ( (CH₃)₃CO^- ) c) Phenoxide ion ( C₆H₅O^- ) d) p-Nitrophenoxide ion ( p-NO₂-C₆H₄O^- ) Phenoxide ions are resonance stabilized, making phenols more acidic than aliphatic alcohols. Thus, (c) and (d) are more acidic than (a) and (b). In p-nitrophenol (d), the -NO₂ group exerts strong -I and -R effects, which further stabilizes