Consider some amount of gas in a container; these gases will be moving randomly in all directions with all possible velocities and these gas molecules. Therefore, acquire kinetic energy based on their velocities. To explain this observed behaviour of gases, Bernoulli proposed a model called the Kinetic Theory of Gas.
The following are the kinetic theory of gases postulates:
- First, the space-volume to molecules ratio is negligible.
- There is no force of attraction between the molecules at normal temperature and pressure. However, the force of attraction between the molecules builds when the temperature decreases and the pressure increases.
- There is a large space between the molecules resulting in continuous motion.
- The free movement of molecules results in a perfectly elastic collision.
- The molecules have kinetic energy due to random movement. But the average kinetic energy of these molecules differs with temperature.
- Molecules exert pressure on the walls of the container.
Kinetic Molecular Theory can be used to explain both Charles’ and Boyle’s Laws.
- Boyle’s Law states that the absolute pressure and volume of a given mass of confined gas are inversely proportional at a constant temperature.
- Charles’ Law states that the volume of a gas increases or decreases by the same factor as its temperature at constant pressure.