DECOMPOSITION KINETICS OF SODIUM PERBORATE CATALYZED BY ETHYLENEDIAMINETETRA-ACETATOMANGANESE(III)

Abstract

The decomposition of sodium perborate in the presence of ethylenediaminetetraacetato-manganese(III) was studied in aqueous solution over the pH range 8.3–10.8 at 50–65°C. The reaction was shown to exhibit second-order kinetics, first-order in each of the reactants. The rate law is

where Y denotes the form of the ligand. Values of k₁ and k₂ were determined at various temperatures. Corresponding activation parameters are ΔH₁* = 36.7 kJ mol⁻¹, ΔS₁* = 182 JK⁻¹ mol⁻¹, ΔH₂* = 32.8 kJ mol⁻¹, ΔS₂* = 194 J K⁻¹ mol⁻¹. Comparison is made with hydrogen peroxide decomposition by manganese complexes.

Key Words:

• Manganese(III)
• complexes
• perborate
• peroxide
• kinetics