Question

Why does the temperature of a substance remain constant during the change of state?

Answer 1

The temperature of any substance remains constant during the change of state because the heat energy supplied is used up in changing the state of matter and also this heat is used for breaking of several bonds or attractive forces. This heat, which does not raise the temperature of the body, is called Latent heat.

During the change of state of any substance, the heat supplied or released is utilized in phase change. Such heat is called latent heat. So, the temperature of any substance remains constant during the change of state.