Answers to AQA GCSE Motion of gas particles

Practice Questions

1.Describe Brownian motion and provide an example.

Brownian motion is the erratic, random movement of particles in a fluid, caused by continuous collisions with molecules of the surrounding medium. An example is dust particles moving randomly in a liquid due to collisions with water molecules.

Other examples could include pollen in water, or any insoluble solid in a liquid. 

2. How is the temperature of a gas related to the kinetic energy of its molecules?

The temperature of a gas is directly proportional to the average kinetic energy of its molecules. As temperature increases, the average kinetic energy of the gas particles also increases.

3. Describe and explain the relationship between gas temperature and pressure at constant volume.

At constant volume, as the temperature of a gas increases, the average kinetic energy of its particles increases, leading to more frequent and forceful collisions with the container walls. This results in an increase in gas pressure.