Answer :
The boiling point of ketones is higher than hydrocarbons due to the presence of a carbonyl group (C=O) in ketones. Here's why:
1. **Hydrogen Bonding**: Ketones can engage in hydrogen bonding between the oxygen of the carbonyl group and hydrogen atoms of neighboring molecules. This intermolecular force results in stronger attractions between ketone molecules, requiring more energy (higher temperature) to break these bonds compared to hydrocarbons.
2. **Dipole-Dipole Interactions**: The carbonyl group in ketones creates a permanent dipole moment, leading to dipole-dipole interactions between ketone molecules. This additional intermolecular force contributes to the higher boiling point of ketones compared to hydrocarbons which lack such polar groups.
3. **Increased Molecular Weight**: Ketones typically have a higher molecular weight compared to simple hydrocarbons. The larger size and mass of ketone molecules result in stronger van der Waals forces between them, further raising the boiling point of ketones.
In summary, the combination of hydrogen bonding, dipole-dipole interactions, and increased molecular weight in ketones collectively contribute to their higher boiling point compared to hydrocarbons.
