KINETIC MOLECULAR THEORY

 KINETIC MOLECULAR THEORY:

The Kinetic Molecular Theory was first proposed by Daniel Bernoulli, a Swiss mathematician. The Kinetic Molecular Theory of gases was elaborated and extended by a number of well known physicist such as James Maxwell (1859) and Boltzmann in (1870). In 1857, Clausius derived the Kinetic equation and deduced all the gas laws from it.

• POSTULATES OF KINETIC MOLECULAR THEORY:

The Kinetic Molecular Theory of gases is based upon following postulates.

• Molecules:

Gases are considered to be composed to minute discreet particles called molecules.

• Mass and size of molecules:

The molecules of a gas are thought to be of the Same mass and size but are different from gas to gas.

• Random motion:

The gas molecules move randomly in the space available and collide with each other and with the walls of container.

• Elastic collision:

When molecules collide with each other, the collisions are perfectly elastic i.e the total kinetic energy remains constant.

• Pressure:

The pressure of gases is due to the elastic collisions of gas molecules with the walls of container.

• Intermolecular distances:

At relatively low pressure, the average distance between the molecules are large as compared with molecular diameters.

• Intermolecular forces:

There are no attractive or repulsive forces between the two.

• Actual volume:

The actual volume of a gas molecules is negligible as compared to the total volume of the container.

• Kinetic energy:

The average kinetic energy of a molecule is directly proportional to the absolute temperature.