Question

Does the substance absorb or liberate any heat energy during the change of phase ?

Answer 1

Yes, the substance absorb and liberate heat energy during the change of state. This heat is known as Latent heat.

Latent heat is the energy absorbed or released by a substance during a change in its physical state (phase) that occurs without changing its temperature. It is normally expressed as amount of heat (in joules or in calories) per unit mass or mole of substance undergoing change of state.