Practical Treatment of Coupled Gas Equilibrium

Equations are derived for the species concentrations in coupled chemical equilibria in the gas phase. This is done both for the method of the direct minimization of the free energy as well as for the equilibrium constant method. The relations developed are such as to allow for the inclusion of detailed real gas effects. The emphasis is on practical problems encountered in the actual calculation of the species and the thermodynamic properties. Expressions are derived for the direct calculation of the concentration derivatives with respect to temperature and density required for the calculation of the derived properties (i. e. specific heats, sound velocities, etc. ). Considerable space is given to discussion of the non-linear numerical methods available for the solution of the non-linear equations for the species concentrations.