Studies on metal carbonate equilibria-part 21 Study of the U(VI)H(2)OCO(2)(g) system by thermal lensing spectrophotometry.
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.
Bidoglio
G
G
Commission of the European Communities Joint Research Centre, Ispra Establishment, 21020 Ispra (Va), Italy.
Cavalli
P
P
Grenthe
I
I
Omenetto
N
N
Qi
P
P
Tanet
G
G