For real gases, how does a change in pressure affect the ratio or pv to nrt?

First the compressibility factor Z = PV/nRT

For the ideal gas, the compressibility factor is Z = 1.

But the real gases The value of Z generally increase with increasing pressure:

1 - At high pressure (the gas hard to compress) : attractive force is weaker than the repulsive force for the gas, and its real molar volume gets larger than the ideal molar volume, and that means z >1.

2 - At low pressure (the gas easy to compress) : attractive force is stronger than the repulsive force for the gas, and its real molar volume gets smaller than the ideal volume, and that means Z<1.