Which property describes the energy required to break intermolecular forces in a liquid?

The property that describes the energy required to break intermolecular forces in a liquid is the heat of vaporization. This term refers to the amount of energy necessary to convert a unit mass of a substance from a liquid into a gas at a constant temperature and pressure. When a liquid is heated, the added energy overcomes the attractive forces between the molecules, allowing them to escape into the gaseous phase.

In contrast, the heat of fusion pertains to the phase change from solid to liquid, which involves breaking the intermolecular forces that hold the solid in a fixed arrangement but does not directly describe the energy involved in changing a liquid to a gas. Specific heat is related to the amount of heat required to change the temperature of a unit mass of a substance by one degree Celsius without a phase change, and caloric value typically refers to the energy content of food. Therefore, heat of vaporization is the appropriate answer as it specifically addresses the energy needed to overcome intermolecular forces in the context of vaporization.