Question
Why does the temperature of the boiling liquid remain constant?
Solution
When a liquid starts boiling, each of the escaping molecules takes away more than the average kinetic energy of the liquid. As such any heat being supplied increases the energy of the remaining molecules to such an extent that it exceeds escaping energy of molecules. Hence, liquid molecules continue to escape as vapours. As a result, the temperature of the boiling liquid, therefore, can not increase till the whole of it has vapourised.
