A sample of a gas has a volume of of 2.0 liters at a pressure of 1.0 atmosphere. When the volume increases to 40 liters, at constant temperature, what will the pressure be?
The final pressure will be 0.05 atm.
This is an example of Boyle's law which states that the volume of a gas varies inversely with pressure, when mass and temperature are kept constant.
Rearrange the equation to isolate