What term is used for heat required to change the state of a substance?

The term used for the heat required to change the state of a substance is latent heat. Latent heat refers specifically to the energy absorbed or released during a phase change, such as during melting, boiling, or sublimation, without changing the substance's temperature. For instance, when ice melts to water, latent heat is what facilitates this transition without increasing the temperature of the water until all the ice has melted.

Enthalpy, while a thermodynamic property that describes the total heat content of a system, includes both the internal energy and the work done by the system but does not specifically refer to the energy required for phase changes. Conductive heat relates to the transfer of heat through direct contact between materials, and Cp heat, commonly known as heat capacity, refers to the amount of heat required to change the temperature of a substance, rather than to change its state.

This distinction makes latent heat the correct term for the energy involved in state transitions.