ISSN:
0538-8066
Keywords:
Chemistry
;
Physical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The kinetics of oxidation of thiosulfate to tetrathionate by trans-dihydroxotetraoxoosmate(VIII) in aqueous alkaline media have been studied. The oxidation follows a rate expression \documentclass{article}\pagestyle{empty}\begin{document}$$ - \frac{{d[{\rm Os(VIII})]}}{{dt}} = k3{\rm K}_{OS} {\rm K}_2 [{\rm S}_2 {\rm O}_3^{2 - }][{\rm Os(VIII})](1 + {\rm K}_{os} {\rm K}_2 [{\rm S}_2 {\rm O}_3^{2 - }])^{ - 1} $$\end{document} where KOs is the formation constant of trans-dihydroxotetraoxoosmate (VIII), and K2 and k3, respectively, represent the formation constants of the intermediate complex involving Os(VIII) and S2O32- and its decomposition constant. The KOs, K2, and k3 values have been computed to be (19.5 ± 3) dm3/mol, (6.12 ± 0.5) and (3.32 ± 0.3) × 10-1 dm3/mol s at 303 K, and I = 0.32 mol/dm3, respectively. The rate law is consistent with a mechanism envisaging the equilibrium formation of an intermediate complex involving Os(VIII) and S2O32-, followed by a rate-determining decomposition of the complex with concomitant electron transfer.
Additional Material:
2 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/kin.550131002
