Non-Ideal Gas (van der Waals equation):  An equation of state for a non-ideal which is commonly used is the van der Waals equation for 1 mol of gas

 P = (R*T)/(V-b) - a/(V^2) 

P = Pressure in Atmospheres 

R = 0.0821 Atm*Liters/Mol*Kelvin

T = Temperature in Kelvin 

V= Volume (in Liters) 

The a and b values are 

Ideal Gas: a = 0, b = 0 (so it reduces to ideal gas equation)

Nitrogen: a = 16.4349 b = 0.0386 

Oxygen: a = 16.5896 b = 0.0318 

1.  For T=300 K and V=10L, calculate the pressure for nitrogen and oxygen and compare the results with ideal gas 

2.  Plot the pressure for oxygen & nitrogen for a range of volumes from 0.1L to 10L (in steps of 0.05L) and compare to ideal gas 

3.  Plot the ratio of the pressure of nitrogen to oxygen and note what happens as the gas is compressed to about 1 L. At this volume, the partial pressure of nitrogen would be much larger than that of oxygen. This is why a scuba diver must be careful when they dive too deep. (With some further study, we could qualitatively reproduce the dive tables).