Question

For any substance, why does the temperature remain constant during the change of state.?

Answer 1

During change of states of matter, old bonds break and new bonds form changing the physical properties like density,volume etc except temperature. It is because energy absorbed or released goes directly into the above bonds process. No energy is used to increase/decrease internal energy.
got it?

Answer 2

During the change of state of any matter heat is supplied to the substance . The molecules of matter observe heat to overcome the force of attraction between the particles at this period of time temperature remain constant . This extra heat is acquired by the molecules in form of hidden heat called latent heat to change from one state of matter to the other state .

hope it helps you.....

plz mark me as brainalist