The Hydrolysis Of Uranium(Vi)

The hydrolysis of uranium(VI) has been investigated in 0.10 mol dm(-3) NaClO4 and KCl and 1.0 mol dm(-3) KNO3 using the potentiometric technique. The results of the data analysis have been combined with data previously obtained from this laboratory and the literature to provide a more definitive description of the hydrolysis behaviour of uranium(VI). The species UO2OH+, (UO2)(2)(OH)(2)(2+), (UO2)(3) (OH)(4)(2+), (UO2)(3)(OH)(5)(+) and (UO2)(4)(OH)(7)(+) have been identified in nitrate media and all but the last of these species in chloride and perchlorate media. The differences in the complexation behaviour in the media may be due to oxoanion binding by the nitrate, a process which has also been observed for sulfate.