Abstract:
The oxidation-reduction reaction between uranium (VI) and vanadium (III) was studied in an aqueous medium with added HCI, NaCI, H2SO4, Na2SO4 and mannitol. The reaction was second order at all the concentrations of reactants and independent of the concentration of HCI, NaCI, Na2SO4, H2SO4 and mannitol used in this work. The rate constant k increases with increase in vanadium (III) concentration whereas it decreases with the increase in uranium (VI) concentration at 5M HCI concentration. The rate constant decreases with the increase in HCI and H2SO4 concentration from 1.5N to 5.25±0.05N and thereafter in increase from 5.25±05N to 10.5N, the range of acid concentration used in this work. The rate constant, k obtained for the redox reaction is in general higher in H2SO4 that than in HCI at a given acid concentration and subsequently the value of experimental activation energy is less in H2SO4 as compared to in HCI solution. The addition of mannitol in the reaction mixture causes a small but consistent decrease in the rate of reaction. Interesting results were obtained for the redox reactions carried out with added HCI, NaCI, H2SO4 and Na2SO4 where the concentration of these additives was varied from 0.02N to 0.2N. The rate of reaction was relatively higher with the added NaCI and Na2SO4 salts with respect to the corresponding acids and the rate also increases with the increase in the concentration of added slats whereas it decreases with the increase in the concentration of the respective acids. The proposed mode of reaction is in agreement with the kinetics results.
Page(s):
105-112
DOI:
DOI not available
Published:
Journal: Nucleus, Volume: 33, Issue: 1--2, Year: 1996