Gay-Lussac's Pressure Law
At constant volume, the pressure of a fixed mass of gas is directly proportional to its absolute temperature.
Formula / equation
p₁ / T₁ = p₂ / T₂
Unit
Pa/K
In depth
In a rigid container, heating makes molecules strike the walls both more often and harder, so pressure rises in proportion to absolute temperature. This is why sealed containers must never be heated, and why tyre pressure readings must be taken when the tyres are cold.
Examples in the real world
An aerosol can bursting in a fire; car tyre pressure rising noticeably after motorway driving.