Question

example 6 - 13: use your knowledge of intermolecular forces to predict whether ch₃coch₃(l) or ch₃ch₂ch₂oh(l) has the higher boiling point.

Explanation:

Step1: Analyze intermolecular forces

• \(CH_3COCH_3\) (acetone): It has dipole - dipole forces. The carbonyl group (\(C = O\)) creates a polar molecule, so there are dipole - dipole interactions between acetone molecules.
• \(CH_3CH_2CH_2OH\) (1 - propanol): It has hydrogen bonding. The \(-OH\) group can form hydrogen bonds. Hydrogen bonds are stronger than dipole - dipole forces.

Step2: Relate intermolecular forces to boiling point

• Stronger intermolecular forces require more energy to break the interactions between molecules.
• Since hydrogen bonds in \(CH_3CH_2CH_2OH\) are stronger than the dipole - dipole forces in \(CH_3COCH_3\), more energy (higher temperature) is needed to convert \(CH_3CH_2CH_2OH\) from liquid to gas.

Answer:

\(CH_3CH_2CH_2OH(l)\) has the higher boiling point.