Question

Describe the process of boiling on the basis of molecular motion.

Answer 1

1. Boiling: The change of liquid to vapours on heating at a constant temperature.
2. Kinetic energy of molecules varies directly with the speed of molecules.
3. More the speed of molecules more the more kinetic energy.
4. On heating, the average Kinetic energy of the liquid molecules increases.
5. The molecules acquire sufficient K.E. needed to overcome the force of attraction of other molecules.
6. These molecules start leaving the liquid surface and also near the walls of the containing vessel.
7. Bubbles can be observed on the walls of the vessel.
8. This results in the agitation in the whole of the liquid and this is called boiling.