Gay-Lussac’s law implies that the ratio of the initial pressure and temperature is equal to the ratio of the final pressure and temperature for a gas of a fixed mass kept at a constant volume. This formula can be expressed as follows:
(P1/T1) = (P2/T2)
Where:
- P1 is the initial pressure
- T1 is the initial temperature
- P2 is the final pressure
- T2 is the final temperature
This expression can be derived from the pressure-temperature proportionality for gas. Since P ∝ T for gases of fixed mass kept at constant volume:
P1/T1 = k (initial pressure/ initial temperature = constant)
P2/T2 = k (final pressure/ final temperature = constant)
Therefore, P1/T1 = P2/T2 = k
Or, P1T2 = P2T1