title: Studies on metal carbonate equilibria-part 21 Study of the U(VI)H(2)OCO(2)(g) system by thermal lensing spectrophotometry.
abstract: Equilibria in the U(VI)H(2)OCO(2)(g) system in 0.5M sodium perchlorate medium at 25 degrees have been studied. By using thermal tensing spectrophotometry (TLS) and a very low total concentration of U(V1) (4 x 10(-6)M) information could be obtained on equilibria involving UO(2)(CO(3))(2-)(2) without complications due to formation of the trimer (UO(2))(3)(CO(3))(6-)(6). The experimental data allowed a precise determination of the equilibrium constant log K(3) = 6.35 +/- 0.05 for the reaction UO(2)(CO(3))(2-)(2) + CO(2-)(3) right harpoon over left harpoonright harpoon over left harpoon UO(2)(CO(3))(4-)(3). The interpretation of TLS data is briefly discussed, as well as the potential use of this technique for studies of the speciation of trace elements in natural water systems.
authors.affiliation: Commission of the European Communities Joint Research Centre, Ispra Establishment, 21020 Ispra (Va), Italy.
authors.forename: G
authors.initials: G
authors.lastname: Bidoglio
authors.forename: P
authors.initials: P
authors.lastname: Cavalli
authors.forename: I
authors.initials: I
authors.lastname: Grenthe
authors.forename: N
authors.initials: N
authors.lastname: Omenetto
authors.forename: P
authors.initials: P
authors.lastname: Qi
authors.forename: G
authors.initials: G
authors.lastname: Tanet