Question

Which among the following compounds has highest boiling point?

विकल्प

• \[\ce{CH3 - CH2 - CH2 - CH2 - OH}\]

• \[\ce{CH3 - CH2 - CH2 - CHO}\]

• \[\ce{CH3 - CH2 - COOH}\]

• \[\ce{CH3 - CH2 - COCH3}\]

Answer 1

\[\ce{CH3 - CH2 - COOH}\]

Explanation:

\[\ce{CH3 - CH2 - COOH}\] compound has the highest boiling point because carboxylic acids are higher boiling liquids than aldehydes. Ketones and even alcohols of comparable molecular masses. This is due to the more extensive association of carboxylic acid molecules through intermolecular hydrogen bonding. The hydrogen bonds are not broken completely even in the vapour phase. In fact, most carboxylic acids exist as a dimer In the vapour phase or in the aprotic solvents.

Hydrogen bonding of RCOOH with H₂O