What causes pressure in a closed container of gas?

1 Answer
Dec 11, 2016

Collisions between the gaseous molecules and the walls of the container, and collisions between the molecules.

Explanation:

At a molecular level, the gaseous particles impact the walls by collision, and the "force per unit area"force per unit area exerted on the the container by the gas is the "pressure"pressure.

Gas laws that relate pressure and temperature for a given volume or given quantity of gas, were perfected and rationalized very quickly, and it allowed early chemists and physicists to have a very shrewd idea of molecular properties, even though they had no way to measure the molecules (but for their macroscopic pressure, and temperature, and volume).