Question

Write down all the postulates of kinetic molecular theory of gases.

Answer 1

To solve this question, we must first understand the whole concept of Kinetic Molecular Theory of Gases. Then we need to assess the postulates and write them in a precise manner and then only we can write the correct answer.

Complete step by step answer
Before we move forward with the solution of this given question, let us first understand some basic concepts:
Kinetic Theory of Gases explains the macroscopic properties of gases, such as volume, pressure, and temperature, as well as transport properties such as viscosity, thermal conductivity and mass diffusivity. The model also accounts for related phenomena, such as Brownian motion. Postulates of Kinetic Molecular Theory of Gases are:
The postulates are useful in the understanding of the macroscopic properties from the microscopic properties.

1. The Gases consist of a large number of particles (atoms and molecules). These particles are extremely small compared to the distance between the particles. The size of the individual particle is considered negligible and most of the volume occupied by the gas is empty space.
2. These molecules are in constant random motion which results in colliding with each other and with the walls of the container. Due to these collisions with the walls, the gases exerts pressure.
3. The collisions between the molecules and with the walls are perfectly elastic and hence when the molecules collide they do not lose kinetic energy due to which molecules never slow down and will stay at the same speed.
4. The average kinetic energy of the gas particles changes with temperature. i.e., The higher the temperature, the higher the average kinetic energy of the gas.
   The molecules do not exert any force of attraction or repulsion on one another except during collisions.

Note: All the gas molecules obey the ideal gas laws only under special conditions of low pressures and high temperatures. The deviations of the real gases, from the ideal gas behaviour, is traced to mainly to wrong or incorrect assumptions in the postulates.