Question

Arrange the following in the increasing order of their boiling point and give a reason for your ordering.

Propan-1-ol, propan-1, 2, 3-triol, propan-1, 3-diol, propan-2-ol

Answer 1

2° alcohols have lower boiling points than 1° alcohol due to a corresponding decrease in the extent of H-bonding because of steric hindrance. Therefore Propan-1-ol has a higher boiling point than Propan-2-ol. Hydrogen group increases, boiling point also increases. Overall increasing order of boiling points is, propan-2-ol < Propan-1-ol < propan-1, 3-diol < propan-1, 2, 3-triol.