Final answer:
Water's high heat of vaporization is largely due to the strong hydrogen bonds between its molecules, requiring significant energy to break. These intermolecular forces exceed those found in simple hydrocarbon molecules, reflecting the unique properties of water.
Step-by-step explanation:
The intermolecular hydrogen bonding in water contributes significantly to its high heat of vaporization. Hydrogen bonds are a strong form of dipole-dipole interaction found in water due to its polar H–O bonds. The high electronegativity of oxygen creates a large partial negative charge on the oxygen and a large partial positive charge on the hydrogen, resulting in strong hydrogen bonds between water molecules.
These hydrogen bonds require a large amount of energy to break, leading to water's high heat of vaporization of 40.65 kJ/mol. In comparison to a hydrocarbon molecule, which consists only of carbon and hydrogen and lacks these strong intermolecular forces, water requires more energy to transition from liquid to vapor, indicating its heat of vaporization is much higher.