For which gases does the ratio of PV to RT equal a constant?

1 Answer
Feb 20, 2017

Presumably, all gases.

By definition, #(PV)/(RT) = Z# is the compressibility factor. When #Z > 1#, the gas's repulsive forces dominate (it takes up more molar volume than its ideal counterpart), and when #Z < 1#, the gas's attractive forces dominate (it takes up less volume than its ideal counterpart).

For any given gas, it is compressible to a given extent determined by its identity. As far as I know, this extent does not change for a given set of conditions (pressure, volume, quantity of gas, temperature, etc) in which we observe a given gas.