Question

The compound that does not liberate $C{O}_2$, on treatment with aqueous sodium bicarbonate solution, is

• A. Benzoic acid
• B. Benzenesulphonic acid
• C. Salicylic acid
• D. Carbolic acid (Phenol)

Answer 1

The correct option is D

Carbolic acid (Phenol)

$NaHC{O}_3⟶N{a}^{+}+HC{O}_3^{-}$

$HC{O}_3^{-}$ is decomposed by acid releasing $C{O}_2$

$HC{O}_3^{-}⟶H_{2}O+C{O}_2$

If acid is stronger than $HC{O}_3^{-}$ then $C{O}_2$ is released. Phenol is less acidic and thus does not liberate $C{O}_2$ with $NaHC{O}_3$. The other carboxylic acid(s) and the benzene sulphonic acid are all stronger acids.