Collection of Czechoslovak Chemical Communications - digital archive 

Abstract

The kinetics and mechanism of oxidation of tartaric acid by bromate ions in sulphuric acid solutions have been studied. As the relation between the concentration of H₃O⁺ ions and the reaction rate constant indicates, the species involved in the reaction are protonized bromate ions (HBrO₃) and tartaric acid molecules. Their interaction is of dipole-dipole nature, as borne out by measurements of the rate constant in dependence on the dielectric constant and on the ionic strength. The activation parameters and the stoichiometry of the reaction have been evaluated. An oscilation behaviour is observed in the presence of a Mn(II) catalyst if bromine is removed from the system constantly. The concentration ranges in which the oscillations occur have been established. Bromine is shown to play a major part in the heterogeneous oscillation system.