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I/GCSE Physics - Kinetic Theory and Gases

Edexcel Physics Kinetic Theory and Gases

July 6, 2021

Kinetic Theory🧐

  • The temperature of a gas is a measure of the average kinetic energy of the particles of a gas.
    • Heating a gas increases KE of particles so they move faster and temperature rises.
  • The pressure of a gas is caused by the forces exerted as moving particles hit the walls of a container. 
    • Faster particles cause more collisions and so a greater force is exerted on the walls.
      • Increasing the temp. of a gas will speed up the particles and therefore increase the pressure.
  • Absolute zero is the temperature at which the pressure of a gas drops to 0.
    • 0°K = -273°C
    • 0°C = 273°K
You will have to know this conversion in I/GCSE Physics.

Calculating Volumes and Pressures🤯

If a volume of a gas increases at a constant pressure, then the pressure decreases.

V1P1 = V2P2

If the temp. of a gas increases at a constant pressure, then the volume increases.

V1 = V2T/ T2

Pressure, volume or temperature can be found by rearranging:

P1V1 / T1 = P2V2 / T2

Drafted by Catrina (Physics)