Pressure & Temperature in Gases (Cambridge (CIE) IGCSE Combined Science: Chemistry): Revision Note

Pressure & temperature in gases

• A change in temperature or pressure affects the volume of gases

• As the air inside a hot air balloon is heated up, it expands and the balloon gets bigger

• This is because the volume of a gas increases as temperature increases

As temperature increases gas volume increases. The density decreases as the volume increases so the balloon rises.

• If you have a gas stored inside a container that is squeezed, the pressure increases as you decrease the volume

• This is what happens in a bicycle pump

Pressure increases as volume decreases in a bicycle pump

• As you compress the bicycle pump, the high pressure allows you to inflate a tyre

• You can feel the force of the high pressure if you put your finger on the end of the pump