Question

why does the temperature of a substance remain constant w​

Answer 1

Answer:

The 'temperature of a substance' remains constant during its melting and boiling point because the change in any state of matter as n solid to liquid or the liquid to a gas involves crossing the 'latent heat of fusion' which causes a change in the intermolecular spacing of the molecules in the substance.

Answer 2

The extra heat supplied to the boiling water is used in the vaporisation of water, which is known as latent heat of vaporisation. That’s why, the temperature of a substance remains constant during its melting