What is effusion and how is it related to diffusion?

Effusion is the process of a gas escaping through a tiny hole, and it's related to diffusion as both involve gas movement.

Effusion is a physical process where gas molecules escape from a container through a small hole or opening. This process is driven by the kinetic energy of the gas molecules and the pressure difference between the inside and outside of the container. The rate of effusion depends on the size of the molecules and their speed, which is determined by the temperature.

Diffusion, on the other hand, is the process by which particles spread out from an area of high concentration to an area of low concentration. It's a result of the random motion of particles, which leads to a net movement towards areas of lower concentration until equilibrium is reached.

The relationship between effusion and diffusion lies in the fact that both processes are examples of passive transport, meaning they occur naturally without the need for energy input. They both involve the movement of gas particles due to kinetic energy. However, while diffusion involves the spreading out of particles in all directions, effusion is a more directed process, with gas molecules moving in a straight line towards the hole they are escaping through.

In terms of the factors affecting these processes, both effusion and diffusion rates increase with higher temperatures, as the gas particles have more kinetic energy and move faster. However, they are inversely proportional to the molar mass of the gas - lighter gases effuse and diffuse faster than heavier ones. This is known as Graham's law of effusion, which states that the rate of effusion of a gas is inversely proportional to the square root of its molar mass.

In summary, while effusion and diffusion are distinct processes, they are closely related in their mechanisms and the factors that influence them. Both are fundamental concepts in understanding the behaviour of gases in chemistry.