Van der Waals equation of state¶
Van der Waals equation of state uses a model which extends the ideal gas law to include the non-zero size of gas molecules and the interactions between them.
Critical parameters¶
Critical parameters of the van der Waals equation of state are such values of volume, pressure, and temperature at which the isotherm has an inflection point whose tangent at that point is zero, i.e. the first and second derivatives of pressure with respect to volume at constant temperature are zero:
\[\left( \frac{\partial p}{\partial V} \right)_T = \left( \frac{\partial^2 p}{\partial V^2} \right)_T = 0\]
Reduced units¶
Reduced units are used in the dimensionless van der Waals equation of state. A reduced quantity \(X_r\) is defined as the ratio of quantity \(X\) to the corresponding critical parameter \(X_\text{c}\).
Contents:
- Critical van der Waals molar volume
- Critical van der Waals pressure
- Critical van der Waals temperature
- Dimensionless van der Waals equation
- Reduced van der Waals pressure
- Reduced van der Waals temperature
- Reduced van der Waals volume
- Van der Waals equation
- Van der Waals molar internal energy
- Van der Waals second virial coefficient