Pressure Changes in a Gas
- If the temperature of a gas remains constant, the pressure of the gas changes when it is:
- Compressed – decreases the volume which increases the pressure
- Expanded – increases the volume which decreases the pressure
Pressure increases when a gas is compressed
- Similarly, a change in pressure can cause a change in volume
- A vacuum pump can be used to remove the air from a sealed container
- The diagram below shows the change in volume to a tied up balloon when the pressure of the air around it decreases:
- Therefore, if the gas is compressed, the molecules will hit the walls of the container more frequently
- This creates a larger overall net force on the walls which increases the pressure