To be able to predict and calculate properties of real
gases.
Kinetic molecular theory makes certain assumptions about gases
that are, in fact, not true for real gases. Therefore, the measured
properties of a gas are often slightly different from the values
predicted by the ideal gas law. The van der Waals equation is a
more exact way of calculating properties of real gases. The formula
includes two constants, a and b, that are unique
for each gas.
The van...