On the complex formation equilibria between dioxouranium(VI) and sulfate ions.
The complexation equilibria between UO2(2+) and SO4(2-) ions have been studied at 25 degrees C in the ionic medium 3 M NaClO4 by potentiometry, by spectrophotometry and by solubility measurements of UO2(IO3)2. The potentiometric investigation was carried out with the Hg-Hg2SO4(s)-SO4(2-) half-cell and glass electrode in the sulfate concentration range 0.005 to 0.07 M. The optical absorbances in the UV-visible region and the solubility data cover the ligand concentration range 0.005 to 0.3 M. The data could be explained by assuming the complexes and equilibrium constants [Table: see text]. The constants in the infinite dilution reference state, log beta1o = 3.08 +/- 0.15 and log beta2o = 4.28 +/- 0.15, estimated by assuming the validity of the specific interaction theory, are practically coincident with literature data.
Dipartimento di Chimica dell'Università "Federico II", Via Cinthia 45, 80126-Napoli. ciavatta@chemistry.unina.it
Liberato
L
Ciavatta
Gaetano
G
De Tommaso
Mauro
M
Iuliano
D009716:Numerical Analysis, Computer-Assisted; D011199:Potentiometry; D012995:Solubility; D013056:Spectrophotometry, Ultraviolet; D013431:Sulfates / Q000737:chemistry*; D017974:Uranium Compounds / Q000737:chemistry*
D013431:Sulfates; D017974:Uranium Compounds; C012597:uranium dioxide