Question

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

Answer 1

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It is due to the latent heat as the heat supplied to increase the temperature of the substance is used up to transform the state of matter of the substance hence the temperature stays constant.

Answer 2

Answer:-

Heat is required to change the phase as well as to increase the temperature. During phase transitions, the heat supplied (called the latent heat) is fully utilised to change the state by overcoming the force of attraction between the particles.  

∴ The temperature remains constant during the change of state.

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