Gay-Lussac's Law

Gay-Lussac's law relates the pressure and absolute temperature of a fixed mass of gas held at constant volume: at constant volume, the pressure ($P$) of a fixed amount of gas is directly proportional to its absolute temperature ($T$), i.e. $P \propto T$, so $P = k_3T$, or $\frac{P}{T} =$ constant (at constant $V$ and $n$). Plotting pressure (in atm) against temperature (in kelvin) at fixed volume gives a straight line called an isochore. This law explains, for example, why the air pressure inside a closed automobile tyre (essentially fixed volume) rises in hot summer weather an …