Collect. Czech. Chem. Commun. 2006, 71, 91-106
https://doi.org/10.1135/cccc20060091

The Autocatalytic Oxidation of Iodine with Hydrogen Peroxide in Relation to the Bray-Liebhafsky Oscillatory Reaction

Anna Olexová, Marta Mrákavová, Milan Melicherčík and Ľudovít Treindl*

Department of Physical and Theoretical Chemistry, Comenius University, 842 15 Bratislava, Slovak Republic

Abstract

The oxidation of iodine with hydrogen peroxide was studied spectrophotometrically and potentiometrically. At low concentrations of HClO4, after induction period (IP), the iodine concentration decreases sigmoidally and IP decreases with decreasing surface area of the solution interphase. We assume that OH radicals are produced via the oxidation of iodide with H2O2 and, by their subsequent reaction with H2O2, the HO2 radicals are formed. By their disproportionation, 2 HO2  ↔   H2O2 + 1O2, very reactive singlet oxygen is produced and the oxidation of iodine can start. The described experimental results are consistent with the Noyes-Treindl mechanism.

Keywords: Autocatalytic reaction; Oxidation of iodine; Bray-Liebhafsky reaction; Singlet oxygen intermediate; Oxidation with hydrogen peroxide; Noyes-Treindl reaction scheme.

References: 33 live references.