A suite of programs, OptimA, OptimB, OptimC, and OptimS compatible with the Unitherm database, for deriving the thermodynamic properties of aqueous species from solubility, potentiometry and spectroscopy measurements

Highlights: • Programs for deriving thermodynamic parameters of aqueous species are described. • OptimA finds G⁰(T, P) of species from results of chemical measurements. • OptimS finds G⁰(T, P) of species by processing UV–Vis absorption spectra. • OptimB finds HKF parameters of a species using its G⁰(T, P) values. • OptimC finds Ryzhenko–Bryzgalin parameters of a species using its pK_dis(T, P). - Abstract: This paper describes four programs for Windows, designed to obtain the thermodynamic properties of aqueous species from experimental data and reporting them in the Unitherm database format (HCh software package). Programs OptimA and OptimS allow users to derive the standard Gibbs free energies of aqueous species from the results of chemical experiments (e.g., potentiometry or solubility) and from ultraviolet–visible (UV–Vis) absorption spectra, respectively; programs OptimB and OptimC enable optimization of the parameters of the revised Helgeson–Kirkham–Flowers equation of state and the modified Ryzhenko–Bryzgalin electrostatic model, respectively, for an aqueous species from its standard Gibbs free energy or stability constant as a function of temperature and pressure