Final answer:
The large difference in boiling points between water and alcohol is due to hydrogen bonding in water molecules.
Step-by-step explanation:
The large difference in boiling points between water and alcohol is due to the presence of hydrogen bonding in water molecules. Both water and alcohol have polar covalent bonds, but water molecules can form hydrogen bonds with each other due to the presence of the hydrogen atom attached to the oxygen atom. These hydrogen bonds require a significant amount of energy to break, resulting in a higher boiling point for water compared to alcohol.
Additionally, water has a high heat of vaporization, which means it requires a large amount of heat energy to change from a liquid to a gas. The extensive hydrogen bonding in water makes it difficult for the water molecules to escape from the liquid phase, further increasing its boiling point.