Thermal physics Watch

Ideal gas law; (NB: Ideal gases are a fiction, they don't actually exist!) PV = nRT;

where P=pressure, V=volume, n=# moles, R=gas constant & T= temp... all in SI units.

Pressure remains constant, number of moles of gas remains constant, therefore; V=RT.

For the reason why the gas constant needs to be applied to temperature, and why the temperature system we use is hundreds of years out of date... well, read Four Laws that Drive the Universe, by Peter Atkins. Worked in the field a long time but never really understood it, until reading that little gem!