Reducing constants for corresponding states and reduced equations of state

✍ Scribed by E.M. Holleran

• Publisher: Elsevier Science
• Year: 1975
• Tongue: English
• Weight: 434 KB
• Volume: 15
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/0011-2275(75)90182-4

✦ Synopsis

It is shown that the three sets of reducing constants (the critical constants, the constants of the intermolecular potential, and the unit-compressibility (UC) constants), all of which can be used as reducing factors for the two-constant system of corresponding states and for two-constant equations of state, are no longer equivalent when three or more constants are needed. For such fluids, there are no reducing constants for temperature and density that can produce a correspondence in the compressibility factor Z, or in the reduced pressure. However, the UC constants do give accurate correspondence of reduced nonideafity, (Z -I); the other two sets of constants are not acceptable. In particular it is shown that the critical constants, which are most commonly used, lead to unavoidable inaccuracy in systems of corresponding states and reduced equations of state.