Which term best defines the measure of heat energy associated with a phase change of a substance?

The term that best defines the measure of heat energy associated with a phase change of a substance is latent heat. Latent heat refers specifically to the energy absorbed or released by a substance during a phase change, such as melting, freezing, vaporization, or condensation, without a change in temperature. For example, when ice melts to become water, it absorbs a specific amount of heat energy, but its temperature remains constant during this transition—the heat energy added is used to change the state rather than increase temperature.

In contrast, enthalpy generally refers to the total heat content of a system, including both internal energy and the energy associated with pressure and volume. Sensible heat is the heat associated with a change in temperature, where the temperature of the substance changes without a phase change. Heat of compression pertains specifically to the energy increase due to compressing a gas and is typically applied in refrigeration and air conditioning contexts but does not directly refer to phase changes. Therefore, latent heat is the most accurate term when discussing heat energy involved in phase transitions.