Nonideal behavior of a gas

You would not have been able to predict that critical temperature and pressure were appropriate for scaling the nonideal behavior of a gas. Until experiments were performed (and you had completed a course in molecular thermodynamics), any other distinguishing features of a gas - boiling point at 1 atm, the triple point, molar volume, etc. - were reasonable choices. And how can we know that the list of parameters in Table 5.12b is sufficient Again, we would not know until we measured and analyzed data for many gases. If all the data lie on the same plot, the list is sufficient. 

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