Pressure

1. Pressure LO: explain how the pressure of a gas depends on the motion of its particles use the equation P/T = constant for a gas in a sealed container.

2. Starter • How do you define gas pressure? • What causes a balloon to pop?

3. Pressure and particles What causes pressure in gases? In a sealed container, the particles repeatedly strike the walls of the container. This causes pressure. What happens if you increase the temperature? more pressure gas gets hotter more kinetic energy more collisions at greater speed

4. Demo – can

5. Particles animation

6. Task • Worksheet - Hot tyres for cars

7. Explain how water boils • Increase the temperature • Lower the pressure above it

8. Summary Increasing the temperature increases the average __________ energy of a gas. The __________ in a gas can be explained in terms of the particles’ collision rate and force of these __________. For a gas trapped inside a container of fixed __________, increasing the __________ temperature increases the pressure in direct __________. collisions kelvin kinetic pressure proportion volume