Question

What is Most Important about Kinetic Molecular Theory?

Answer 1

1. Among the three states of matter, the gaseous state is the most well understood. The laws governing gaseous behaviour are more uniform.
2. The well-known laws of gaseous behaviour, Boyle's Law, Charles' Law, Graham's Law, Dalton's Law and Avogadro's Law, were, at the time of their enunciation, merely empirical generalisations based on experimental observations. There was no sound theoretical basis for these laws.
3. The Kinetic Molecular Theory of Gases, developed by Kronig, Clausius, Maxwell and Boltzmann, provided a theoretical basis for the empirical gas laws.
4. The Kinetic Molecular Theory of Gases is based on the following postulates.
5. A gas consists of a large number of minute particles, called molecules. The volume occupied by the molecules is negligible compared to the volume occupied by the gas.
6. The molecules are in a state of constant, rapid motion and collide randomly with each other and with the walls of the container.
7. Collisions of gas molecules with each other and with the walls of the container are perfectly elastic. This means that there is no net loss of kinetic energy as heat etc. in the collision.
8. The gas molecules are completely independent of each other. There are no forces of attraction between the gas molecules.
9. The pressure of a gas is due to the bombardment of molecules on the walls of the container.
10. The motion of the gas molecules is governed by the laws of classical mechanics (such as Newton's Laws).
11. Any gas that obeys all the above postulates is called an Ideal Gas. The above postulates are only approximately valid for gases in the real world.

Hence, the kinetic molecular theory of gases provides a sound theoretical basis for the well-known empirical gas laws.