Kinetic Theory of Gases

Kinetic Theory of Gases

kinetic theory of gases is indeed a simple, historically relevant classical model of the thermodynamic behaviour of gases that established many fundamental thermodynamic concepts.

Gas has always been described by the model as a large number of identical submicroscopic particles (atoms or molecules) that are all in constant, rapid, random motion. Their size has been assumed to be much smaller than the average particle distance.

Irregular elastic collisions happen between the particles and with the enclosing walls of the container. The basic model describes the ideal gas and takes into account no other particle interactions. Moreover, the model aids in understanding related phenomena such as Brownian motion.

The kinetic theory of gases basically describes macroscopic properties of gases like volume, pressure, and temperature, as well as transport properties like viscosity, thermal conductivity, and mass diffusivity.

The model as well takes into account related phenomena like Brownian motion. Traditionally, the kinetic theory of gases was the first explicit application of statistical mechanics ideas.

The atoms or molecules of a gas are viewed as constantly moving point masses with large inter-particle distances that can collide perfectly elastically, according to the kinetic theory of gases. The implications of these assumptions are particles, point masses, negligible volume particles, the volume of gas and so on.

Kinetic Theory of Gases Postulates

• Gases have been made up of a large number of tiny particles (atoms and molecules). Such particles are extremely small in comparison to the distance between them. The individual particle size is defined as negligible, and the majority of the volume occupied by the gas is empty space.
• These molecules seem to be in constant random motion, resulting in collisions with one another and with the container’s walls. Whenever the molecules of gas collide with the walls of a container, they impart momentum to the walls and this results in the generation of a measurable force. So, if we divide this force by the area, we get the pressure.
• Collisions among molecules and walls are completely elastic. It thus means that when the molecules collide, they retain their kinetic energy. Molecules don’t ever slow down and will always move at the same rate.
• The average kinetic energy of the gas particles has been affected by temperature. That is, the higher the temperature, the greater the average kinetic energy of the gas.
• Apart from when they collide, the molecules have no attraction or repulsion for one another.

FAQs

What is the kinetic theory's primary importance?

Kinetic theory gives a better understanding of gases by assuming that gas is made up of rapidly moving atoms or molecules.

What are the kinetic model's key points?

The most basic kinetic model is based on the assumptions that: (1) gas has been composed of a large number of identical molecules moving in random directions, separated by large distances relative to their size; (2) its molecules collide perfectly elastically (no energy loss) with each other and with the container walls, but otherwise do not interact; and (3) the transition of kinetic energy between molecules is heated.