The solubility of BaCO 3 (cr) (witherite) in CO 2 -H 2 O solutions between 0 and 90°C, evaluation of the association constants of BaHCO 3 + (aq) and BaCO 3 0 (aq) between 5 and 80°C, and a preliminary evaluation of the thermodynamic properties of Ba 2+ (aq