Assertion : The pK_a of acetic acid is lower | vedclass

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(C) lower $pK_a$ value indicates a stronger acid. Acetic acid $(pK_a \approx 4.76)$ is a stronger acid than phenol $(pK_a \approx 10)$. The acidity of

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If the Assertion is correct but Reason is incorrect.

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(C) lower $pK_a$ value indicates a stronger acid. Acetic acid $(pK_a \approx 4.76)$ is a stronger acid than phenol $(pK_a \approx 10)$. The acidity of carboxylic acids is due to the resonance stabilization of the carboxylate ion,where the negative charge is delocalized over two highly electronegative oxygen atoms in equivalent resonance structures. In contrast,the negative charge in the phenoxide ion is delocalized over the carbon atoms of the ring,which is less effective. Therefore,the Assertion is correct,but the Reason is incorrect.

List-$I$	List-$II$
$(a)$ $R-COCl \to R-CHO$	$(i)$ $Br_2 / NaOH$
$(b)$ $R-CH_2-COOH \to R-CH(Cl)-COOH$	$(ii)$ $H_2 / Pd-BaSO_4$
$(c)$ $R-CONH_2 \to R-NH_2$	$(iii)$ $Zn(Hg) / \text{Conc. } HCl$
$(d)$ $R-CO-CH_3 \to R-CH_2-CH_3$	$(iv)$ $Cl_2 / \text{Red } P, H_2O$

Assertion : The $pK_a$ of acetic acid is lower than that of phenol.
Reason : Phenoxide ion is more resonance stabilised.

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Assertion : The $pK_a$ of acetic acid is lower than that of phenol.Reason : Phenoxide ion is more resonance stabilised.