What does specific latent heat of vaporization refer to?

The specific latent heat of vaporization refers to the amount of energy required to change a unit mass of a substance from a liquid to a gas at its boiling point, without a change in temperature. This energy is needed to overcome the intermolecular forces that bind the molecules together in the liquid state.

During the phase transition, the temperature remains constant even though energy is being added to the system. This is characteristic of latent heat processes, where the energy supplied does not increase the temperature but rather facilitates a change of state. In the case of vaporization, this energy input allows the molecules to gain enough energy to break free from the liquid phase and enter the gas phase.

It's important to note that the other concepts involve different phase changes or energy requirements that do not relate specifically to vaporization. For instance, the energy required to melt a solid is associated with the latent heat of fusion, while the processes of solidification and freezing involve different energy interactions related to cooling and bond formation in a liquid converting to a solid.