BITSAT2014ChemistryGeneral Organic ChemistryActual
The ionization constant of phenol is higher than that of ethanol because :
Options
- APhenoxide ion is bulkier than ethoxide
- BPhenoxide ion is stronger base than ethoxide
- CPhenoxide ion is stabilized through delocalization
- DPhenoxide ion is less stable than ethoxide
Correct answer
C. Phenoxide ion is stabilized through delocalization
Step-by-step solution
The acidic nature of phenol is due to the formation of stable phenoxide ion in solution C ₆ H ₅ OH + H ₂ O C ₆ H ₅ O _ Phenoxide ion ⁻+ H ₃ O ⁺ The phenoxide ion is stable due to resonance. The negative charge is delocalized in the benzene ring which is a stabilizing factor in the phenoxide ion and increase acidity of phenol. wheras no resonance is possible in alkoxide ions ( RO ⁻ ) derived from alcohol. The negative charge is localized on oxygen atom. Thus, alcohols are not acidic.