A kinetic-equilibrium study of a triiodide concentration maximum formed by the persulfate-iodide reaction

• Autores: Arthur E. Burgess, John C. Davidson
• Localización: Journal of chemical education, ISSN 0021-9584, Vol. 89, Nº 6, 2012, págs. 814-816
• Idioma: inglés
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• Resumen

  • The presence of triiodide, I3-, throughout the lifetime of a persulfate-iodide reaction with persulfate in excess, is controlled by an opposing effect of falling iodide concentration and rising iodine concentration. This brings triiodide to a concentration maximum, [I3-]max, which can be studied by UV-visible spectroscopy using absorbance measurements taken over an extended iodine clock time-scan. Equilibrium and conservation equations can be combined so that, together with [I3-]max, a value of the constant K for the equilibrium established between iodine, iodide, and the triiodide complex ion can be obtained.