Kinetics and mechanism of the catalysed decomposition of sodium perborate by the ethylenediaminetetraacetatoiron(III) complex

The rate of reaction of Fe^IIIY] (Y = EDTA anion) with NaBO₃ was studied in aqueous 0.1 M NaNO₃ at various temperatures. The observed rate constant,k _obs = kKKK ₁FeEDTA(H₂O)^-]/{H⁺] + KK ₁FeEDTA(H₂O)^-]}applies over the pH range studied. The monohydroxy complex, FeEDTA (OH)]^2– is the catalyst which reacts with the peroxy ion to produce a violet intermediate complex. The composition of perborate confirms to Michaelis–Menten kinetics, the rate-determining step involving breakdown of the intermediate complex. The activation enthalpy and activation entropy were calculated.