For many purposes we can treat methane $(C{H}_4)$ as an ideal gas at temperatures above its boiling point of $-161.C.$

Suppose the temperature of a sample of methane gas is lowered from $-33\mathrm{.}0C$ to $-57\mathrm{.}0C,$ and at the same time the pressure is increased by $15\mathrm{.}0\%.$