Kinetic Molecular Theory and Gas Laws Explain Properties of Gas Molecules

The observations of different gas properties, as expressed by the various gas laws derived by Boyle, Charles, Gay-Lussac, and Avogadro, follow conceptually from kinetic molecular theory.

The pressure exerted by a gas results from the impact of constantly moving particles on the walls of its container.

Decreasing the volume of the container, while keeping the number of moles and temperature constant, brings the gas particles closer together, reducing their interparticle spacing.

In this smaller volume, the density of the gas and collision frequency — the frequency of molecule-wall collisions — increases. Therefore, the pressure exerted by the gas increases. The inverse relationship between pressure and volume is given by Boyle’s law.  

Adding more moles of gas to the container at constant temperature increases the gas density, and hence, the collision frequency. 

To maintain the initial pressure, the volume must expand. This direct relationship between volume and moles is given by Avogadro’s law. 

Now, consider the number of moles is kept constant and the temperature is raised. Because the average kinetic energy of gas particles increases proportionally with temperature, the particl