Question

Although phenoxide ion has more number of resonating structures than carboxylate ion, carboxylic acid is a stronger acid than phenol. Why?

Answer 1

Answer: The carboxylate ion ismore stable than the phenoxide ion. This is because in thephenoxide ion, the negative charge resides on one electronegative oxygen atom and the lesser electronegative carbon atoms. Consequently their contribution towards resonancestabilisation of the phenoxide ionis less.

Answer 2

Hey !!

The dolocalisation of benzene electrons contributes little towards the stability of phenoxide ion. The carboxylate ion is much more resonance stabilized than phenoxide ion. So, it is easier to lose a proton than phenol. Hence, carboxylic acid is a stronger acid than phenol.

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