# Critical Point on Van der Waals Isotherms

The critical point is the unique point on the original van der Waals isotherms (before the Maxwell construction) where both the first and second derivatives of P with respect to V (at fixed T) are zero. Use this fact to show that:

V_c = 3Nb, P_c = (1/27) (a/b2), kT_c = (8/27) (a/b).

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The critical point is the unique point on the original van der Waals isotherms (before the Maxwell construction) where both the first and second derivatives of P with respect to V (at fixed T) are zero. Use this fact to show that:

Vc = 3nb, Pc = ...

#### Solution Summary

Word document explains how to show that certain equations hold using properties of van der Waals isotherms.

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