If the temperature of a sealed container is doubled (in Kelvin) while volume remains fixed, what happens to the internal pressure?

• A. Pressure remains constant
• B. Pressure doubles
• C. Pressure halves
• D. Pressure increases by a factor of four

Answer: (B)

When volume and the amount of gas are fixed, pressure is directly proportional to temperature measured in kelvin (PV = nRT). Since n, R, and V don’t change, P ∝ T. If the temperature in kelvin is doubled, the pressure must also double: P2 = 2P1. Remember to use Kelvin for the temperature in this relationship; Celsius values must be converted before applying the proportionality. So the pressure increases by a factor of two.