Thermodynamical data of uranyl car bonate complexes from absorption spectroscopy

Abstract

Aquatic uranyl carbonate complexes play an important role in the hydrogeology of uranium mining areas and nuclear waste disposals. Many publications are available for the stability of uranyl carbonate complexes, but thermodynamical data like the enthalpy or entropy are rare. We determined thermodynamical data from spectroscopic studies for the uranyl carbonate complex UO2(CO3)34- in the temperature range from 5 °C to 70 °C. The reaction enthalpy the reaction entropy were determined to be -36.25 ± 4.31 kJ/mol and 297.082 ± 13.839 J/(K •mol), respectively.