'If heat energy is added to a mixture of solid and liquid at equilibrium ,the solid is gradually converted to liquid while the temperature remains constant' In the above process the heat energy is added then how does temperature remains constant?

CBSE Class 11-science Answered

"If heat energy is added to a mixture of solid and liquid at equilibrium ,the solid is gradually converted to liquid while the temperature remains constant" In the above process the heat energy is added then how does temperature remains constant?

Asked by Abhimanyu Charan | 30 Nov, 2013, 10:01: AM

Expert Answer

This is because of 'Latent heat'. Let us understand this with the help of an example of Ice and Water.

Ice is a solid substance. During melting, the temperature of the system dosenot change after the melting point is reached, till all the ice melts. This happens even though we continue to supply heat.
This heat energy gets used up in changing the state by overcoming the forces of attraction between the particles. As this heat energy is absorbed by ice without showing any rise in temperature, it is considered that it gets hidden into the contents of the beaker and is known as ‘Latent heat’. The word ‘Latent’ means ‘Hidden’.
When all the ice has melted to form water, further heating increases the kinetic energy of the particles due to which the temperature of water rises.
Particles in water at 0^oC (273 K) have more energy as compared to particles in ice at the same temperature.

Answered by Hanisha Vyas | 02 Dec, 2013, 11:39: AM