The kinetics of the complex formation between iron(III)–ethylenediaminetetraacetate and hydrogen peroxide in aqueous solution Academic Article uri icon


  • The kinetics of the formation of the purple complex [FeIII(EDTA) O2]3-, between FeIII-EDTA and hydrogen peroxide was studied as a function of pH (8.22-11.44) and temperature (10-40°C) in aqueous solutions using a stopped-flow method. The reaction was first-order with respect to both reactants. The observed second-order rate constants decrease with an increase in pH and appear to be related to deprotonation of Fe III-EDTA ([Fe(EDTA)H2O]-⇔Fe(EDTA)OH] 2-+H+). The rate law for the formation of the complex was found to be d[FeIIIEDTAO2]3-/dt=[(k 4[H+]/([H+]+K1)][Fe III-EDTA][H2O2], where k4=8. 15±0.05×104 M-1s-1 and pK 1=7.3. The steps involved in the formation of [Fe(EDTA)O 2]3- are briefly discussed. © 2004 Elsevier B.V. All rights reserved.

author list (cited authors)

  • Sharma, V. K., Millero, F. J., & Homonnay, Z.

citation count

  • 10

publication date

  • September 2004