Question

State the postulates of Kinetic Molecular Theory.

Answer 1

According to kinetic theory:

1. Gases consist of particles that are in constant, random motion. They continue to move in a straight line until they collide with each other or the walls of their container.
2. Particles are point masses with no actual volume, we normally do not consider their size in ideal gases. The particles are very small compared to the space between them.
3. No molecular forces act between them means there is no attraction or repulsion between the particles.
4. Gas pressure is due to the molecules colliding with the walls of the container. These collisions are elastic i.e there is no change in energy of either the particles or the wall upon collision. No energy is lost or gained from collisions.
5. The time it takes to collide is negligible compared with the time between collisions.
6. The kinetic energy of a gas is measured in Kelvin. Each gas molecules have different speeds, but for the temperature and kinetic energy, the average of these speeds is considered.
7. The average kinetic energy of a gas particle is directly proportional to the temperature.
8. All gases at a given temperature have the same average kinetic energy.
9. Lighter gas molecules move faster than heavier molecules.