Kinetic Theory

KINETIC THEORY

The kinetic theory or kinetic-molecular theory of gases helps to explain the behavior of a hypothetical ideal gas. According to the theory, gases are made from tiny particles that move in a random and straight-line fashion. They do not move slowly and they do not stop moving at normal temperature, making collisions with each other and with the walls of the container they are in. This was the first theory that is based primarily on molecular collisions rather than static forces between the molecules. According to the kinetic theory, different sizes of the gaseous particles can give them different individual speeds.

According to this theory, the following things are true:

• Gases consist of constantly and randomly moving particles that travel in a straight line.

• Gas particles are point masses that have no volume of their own.

• There are no attractive or repulsive forces in place.

• Gas pressure comes directly from collisions between the molecules and the walls of the container.

• No energy is lost in the movement or collisions of the molecules.

• There is no time for the collision itself compared to time between collisions.

• The kinetic energy of a gas is a measure of the Kelvin temperature.

• Individual gas molecules behave differently by size but the total kinetic energy is an average of their speeds.

• The kinetic energy is directly proportional to the temperature.

• All gases at the same temperature will have the same average kinetic energy.

• Lighter gas molecules move faster than heavier gas molecules.

The temperature of a gas is the measure of its kinetic energy. The kinetic energy of a particle is related to its velocity according to this equation: Kinetic energy equals 12