Question

Carboxylic acids have higher boiling points than aldehydes, ketones and even alcohols of comparable molecular mass. It is due to their

• A. More extensive association of carboxylic acid via van der Waals force of attraction
• B. Formation of carboxylate ion
• C. Formation of intramolecular H-bonding
• D. Formation of intermolecular H-bonding

Answer 1

Answer: (D)

Due to formation of stronger intermolecular H-bonding in carboxylic acid, association occurs. Hence, boiling point increases and become more than the boiling point of aldehydes, ketones and alcohols of comparable molecular masses.

Acid > alcohol > aldehyde > ketone

$\underset{AsextentofH-bonddecreasessoB.P.decreases}{\to }$