Hydrolysis Constants of Plutonium(lll) and Americium(lll)

The Determination of the First Hydrolysis Constant of Eu(lll) and Am(lll)

“…Our values are related to an ionic medium of 0.7 M NaCl and are in good agreement for Am(III) with other recent values for a medium of 1.0 M Naa04. By contrast, our value for Eu(Iir) in 0.7 M medium does not agree well with those reported in references [13] and [14] for l.OM medium. Since the radii of Am(III) and Eu(III) are similar, with that of Eu(III) being ^^tly smaller [15], we would expect the value of log *0(Eu) to be slightly more positive than that of Am.…”

Proceedings of the workshop on geochemical modeling

“…EQ3NR calculations of the distribution experiments were done by defining fictitious species to simulate Am(III) in an organic phase and by estimating a logK for these species from the experimental distribution coefficients. Calculations of Am(III) distribution and average ligand number (for the potentiometric titrations) showed good agreement with the data of Lundqvist (1982) and Caceci and Choppin (1983), but underpredicted the average ligand number of Nair et al (1982) over the pH range of 4 to 8.…”

“…The formation constant for AmOH 2+ was taken as the average of values reported by Lundqvist (1982), Caceci and Choppin (1983), Nair et al (1982), and Edelstein et al . (1983), corrected to \x = 0.…”

Studies on Stability Constants of Europium(III) Carbonate Complexes and Application of SIT and Ion-Pairing Models

“…The advantage of using the D 0 values obtained in this work over the literature hydrolysis and buffer complexation constants in calculating the formation constants of carbonate complexes lies in the fact that our values do not suffer from the literature value uncertainties. The comparison among the first hydrolysis constants reported for Eu(III) using different techniques (3,4) clearly indicates that the values vary and the judicial selection of a particular value is not always an easy task. While the former method has an advantage in this aspect, it is partially offset by the uncertainty introduced in the extrapolations needed to compute D 0 values for the actual experimental conditions.…”

“…In recent years, the hydrolysis constants of Am(III) and Pu(III) by pH titration [3], of Am(III) and Eu(III) by solvent extraction [4], and of Am(III) by solubility measurements [5] have been reported. Distribution methods have been successfully employed in characterizing the carbonate complexes of Np(V) with TOMA-TTA [6] and TTA-Phen [7] synergic systems, of Am(III) with HDBM [8] and TBP [9], and of Eu(III) with TBP [9][10][11].…”