Application of Benedict-Webb-Rubin Equation of State to Ammonia.

Abstract

have shown, methods of approximating the acentric factor do not always match the value calculated from the definition.The exponents of Tc -T do not correlate well because this simple formula is not exact. As can be seen from the figures, the latent heat varies in a manner slightly more complicated than (Tc -T)n. CONCLUSIONThe latent heat equation L = k (Tc -T)n has been fitted for 44 substances with an average value of n of 0.378. This value is little different from 0.38 proposed by Watson (58) in 1931. The exponent was found to be a random variable against various parameters that might have been expected to correlate it. P-H Diagram for Freon 116, undated. (29) DuPont de Nemours, E. I. & Co., Wilmington, Del., DuPont Tech. Bull. B-2,1962.

Extended Benedict-Webb-Rubin equation of state. Application to eight fluorine compounds

“…However, as has been discussed by Lin and Naphtali (22), it is not possible to determine a unique set of constants for this equation that will correlate accurately liquid-vapor phase behavior, as well as a gas phase P-V-T behavior, over a wide range of temperature and pressure. Several solutions to this problem have been proposed in these references: One or more of the coefficients are varied for use in the different regions of the P-V-T surface (42); various modifications in the functional representation are utilized; individual sets of constants are developed, one based on gas-phase P-V-T data and another on data in the liquid region (38).…”