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Which of the following statements is correct for the stability of ions of ethyl alcohol and phenol :
A
Delocalisation of $\pi$-electrons in phenoxide ion
B
Delocalisation of electrons in ethoxide ion
C
Inductive effect of ethyl and phenyl group
D
Localisation of $\pi$-electrons in phenoxide ion
Detailed Solution
Phenol is more acidic than ethanol because the phenoxide ion is more stable than the ethoxide ion.
In the phenoxide ion, the negative charge on oxygen is delocalised into the benzene ring through resonance (it appears at the ortho and para positions), which stabilises the ion.
In the ethoxide ion, the negative charge stays localised on oxygen, and the ethyl group (+I effect) intensifies it, making the ion less stable.
So the stability is explained by delocalisation of $\pi$-electrons in the phenoxide ion.
In the phenoxide ion, the negative charge on oxygen is delocalised into the benzene ring through resonance (it appears at the ortho and para positions), which stabilises the ion.
In the ethoxide ion, the negative charge stays localised on oxygen, and the ethyl group (+I effect) intensifies it, making the ion less stable.
So the stability is explained by delocalisation of $\pi$-electrons in the phenoxide ion.