Question

A solid melts its temperature remains constant explain

Answer 1

When a solid melts, its temperature remains the same because the heat energy supplied is utilised to break the bonds between the particles of matter. Therefore, the temperature of the solid does not change till all the solid melts.

The temperature of a substance remains constant at its melting and boiling points until all the substance melts or boil because the heat supplied is continuously used up in changing the state of the substance by overcoming the forces of attraction between the particles. This heat energy absorbed without showing any rise in temperature is given the name latent heat of fusion/latent heat of vapourisation.

When heat energy is supplied to ice it changes into water and then to vapor. If we cool the steam it gets converted into water and further cooling of water changes into ice.Here the heat energy is used up in changing the state of matter. the heat is used to increase the kinetic energy of the particles of ice to such an extent that they break away from the rigid lattice structure of the solid form, ice, and move around freely to form the liquid form, water. So, until all the ice has melted, the heat absorbed does not raise the temperature of the ice-water mixture. In the same way the temperature doenot change while a liquid is boiling. This heat, which does not raise the temperature of the body, is called Latent Heat.