Improving Internal Consistency of Standard State Thermodynamic Data for Sulfate Ion, Portlandite, Gypsum, Barite, Celestine, and Associated Ions

Thermochemical measurements in the gypsum-portlandite-water system are actually better than those reflected in the thermodynamic properties of CODATA. It is argued that by careful choice of starting points and pathways and with new data, improvements in standard state properties can achieve improved consistency with solubilities of gypsum, portlandite, barite, witherite, celestine, and strontianite if better entropy estimates of these minerals are made.