Question

How does gas exerts pressure on its containers?

Answer 1

Hint: We know that there are three states of matter namely solid, liquid and gas. The particles in gaseous state are very far from each other. Gases do not have any specific shape, it takes the shape of the container in which it is kept.

Complete step by step answer:
Let’s discuss the pressure exerted by the gas. A gas exerts uniform pressure in all directions on the walls of the container in which it was enclosed. It is because of the random motion of the gaseous particles. We know that gaseous particles are very far from each other. So, the intermolecular force between them is very weak. The gaseous particles are in continuous random motion and collide with the wall of the container. These collisions exert force on the walls of the container.

Additional Information:
An instrument called a barometer is used to measure the atmospheric pressure. Mercury is a liquid with very high density, and is normally used in a barometer because it does not stick to the surface of the glass tube. Mercury is not also volatile at room temperature. Therefore, there are hardly any vapors of mercury above the liquid column and their pressure, if any, can be neglected.

Note: We know that the Earth is surrounded by a blanket of air which is about 800 km thick. Air is a mixture of a number of gases. Due to the gravity of the Earth, air is pulled towards it and exerts pressure on its surface. This pressure is termed as atmospheric pressure. The SI unit of pressure is Pascal.