Correction of Holloway's (1977) adaptation of the modified Redlich-Kwong equation of state for calculation of the fugacities of molecular species in supercritical fluids of geologic interest

Consideration of constraints imposed on fugacity coefficients by the Gibbs-Duhem equation and those inherent in the Redlich-Kwong equation of state (Redlich and Kwong, 1949) and its modification by de Santis et al. (1974) indicates that Holloway's (1977) adaptation of the Redlich-Kwong equation for calculating fugacity coefficients of molecular species in gas mixtures is in error. Revised calculations using the correct equation lead to much smaller departures from ideality than those generated by Holloway.