Pseudo-Pure Fluid Equation of State
Pseudo-pure fluid equation of state is the term used when the thermodynamic properties of a mixture of fixed composition are represented by a generalized Helmholtz free energy equation of state for a pure fluid, as detailed by Lemmon.
E. Lemmon
"Pseudo-Pure Fluid Equations of State for the Refrigerant Blends R-410A, R-404A,R-507A, and R-407C"
International Journal of Thermophysics, Vol. 24, No. 4, July 2003
Pseudo-pure equations of state are used in EES to provide property data for R4xx and R5xx refrigerant mixtures. In most cases, the property estimates resulting from the pseudo-pure fluid equation of state provide acceptable accuracy. The uncertainty of the results increases in the vicinity of the the critical point, particularly for the specific heat. EES will issue a warning if the specific heat calculation is not considered to be reliable.