Complex formation between Fe(II) and inorganic anions. Part 1.—Effect of simple and complex halide ions on the Fe(II)+H2O2 reaction

Abstract

The addition of halide ions causes an increase in the observed bimolecular rate constant k₀ for the Fe(II)+H₂O₂ reaction, ultimately reaching a limiting value depending on the anion. This is interpreted in terms of complex formation between ferrous ions and halide ions, with the complex reacting faster than the hexa-aquoferrous ion with hydrogen peroxide. From the variation of k₀ with the concentration of halide, the type of complex formed can be distinguished. Heats and entropies of formation of the complexes are determined. Entropies and energies of activation for the reaction of the complexes with H₂O₂ are determined.