Question

(a) What do you understand by the change of phase of a substance?

(b) Is there any change in temperature during the change of phase?

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

Answer 1

(a) A change from one state (solid or liquid or gas) to another at a constant temperature is called the change of phase.

(b) There is no change in temperature during the change of phase.

(c) Yes, energy (in form of latent heat) is absorbed or liberated during the change of phase.