Question

Explain the following.
The temperature remains constant during boiling of a liquid.

Answer 1

The temperature remains constant during boiling of water even though heat is supplied constantly because all the heat energy provided is used up in changing the state of water from liquid to gaseous water vapour. Therefore all the heat energy provided to the liquid increases the kinetic energy of the particles and temperature doesn't increase. So supplied heat energy is used to increase kinetic energy of molecules.