Account for the following:

(i) CH₃CHO is more reactive than CH₃ COCH₃ towards reaction with HCN.

(ii) The carboxylic acid is a stronger acid than phenol.

(i) CH₃COCH₃ is sterically hindered than CH₃CHO due to the presence of alkyl group on both sides of the carbonyl carbon, making them less reactive towards nucleophilic attack because both methyl groups have electron releasing tendency due to -I effect. These alkyl groups make ketone less reactive by donating an electron to a carbonyl group. Therefore, acetaldehyde is more reactive towards reaction with HCN.

(ii) Carboxylic acids are acidic due to resonance stabilisation of carboxylate anion and in phenols, the acidic character is present due to resonance stabilisation of phenoxide anion. Carboxylic acids are more acidic than phenols because the negative charge in carboxylate anion is more spread out compared to the phenoxide ion, as there are two electronegative O-atoms in carboxylate anion compared to one in phenoxide ion. In the resonance structures of carboxylate anion, the negative charge is present on the O-atoms, while in the resonance of phenoxide ion, a negative charge is also present on the electropositive carbon atom, which leads to less stability of phenoxide ion than carboxylate anion.