Question

for any substance why does the temperature remain constant during the change of state​

Answer 1

Answer:

The temperature remains constant during the change of state because the heat energy which is supplied to change the state of matter is used in breaking the intermolecular forces and other attractive forces. Hence the temperature remains constant as all the heat is used up and no external heat is released or absorbed.

Answer 2

Because with the increase of temperature, more number of particles get enough kinetic energy to go into the vapour state. Hence temperature remains constant during the change of state.