Question

Boiling points of carbonyl compounds are higher than those of alkanes due to:

• A. hydrogen bonding
• B. dipole-dipole interactions
• C. van der Waals' forces
• D. all of the above

Answer 1

The correct option is B dipole-dipole interactions

The boiling points of aldehydes and ketones (carbonyl compounds) are higher than boiling point of alkanes due to polar and stronger carbon-to-oxygen double bond result in increase dipole-dipole interaction between molecules of carbonyl compounds which are much stronger than Van der Waals forces between molecules of alkanes. So, energy required to break the interaction between carbonyl compound molecules is more than that of forces between molecules of alkane and hence boiling point is higher. Hence, correct option is (b).