Question

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

Answer 1

• During a change of state, the temperature remains constant. This is because all the heat supplied to increase the temperature is utilised in changing the state by overcoming the forces of attraction between the particles.
• Therefore, this heat does not contribute to increasing the temperature of the substance.
• Hence, the heat given out during this change of state is called latent heat (latent heat of oxidation or latent heat of vaporization).