Law of corresponding states

The law of corresponding states is an empirical law encapsulates the finding that the equations of state for many real gases are remarkably similar when they are expressed in terms of reduced temperatures ($T_{r}=T/T_{c}$), pressures, ($p_{r}=p/p_{c}$) and volumes ($V_{r}=V/V_{c}$). This law was first described by Johannes Diderik van der Waals in 1913 (Ref. 1).

For argon, krypton, nitrogen, oxygen, carbon dioxide and methane one has (Ref. 4)

${\frac {p_{c}V_{c}}{RT_{c}}}\approx 0.292$

References

1. Johannes Diderik van der Waals "The law of corresponding states for different substances", Proceedings of the Koninklijke Nederlandse Akademie van Wetenschappen 15 II pp. 971-981 (1913)
2. J. de Boer and A. Michels "Contribution to the quantum-mechanical theory of the equation of state and the law of corresponding states. Determination of the law of force of helium", Physica 5 pp. 945-957 (1938)
3. Kenneth S. Pitzer "Corresponding States for Perfect Liquids", Journal of Chemical Physics 7 pp. 583-590 (1939)
4. E. A. Guggenheim "The Principle of Corresponding States", Journal of Chemical Physics 13 pp. 253-261 (1945)