Calorimetric investigation of kinetics of solid phase dissolution: Calcium carbonate dissolution in aqueous EDTA solution

The calorimetric method for examination of the kinetics of solid phase dissolution is presented. The thermograms are interpreted by considering the heat evolution due to the reaction as well as the heat transfer in the calorimeter. The kinetic interpretation is based on the change of particle surface area during the dissolution process. The experimental results confirm the applicability of the proposed method. The rate constant and the enthalpy of dissolution of solid CaCO3 in aqueous EDTA and NaOH solutions are determined. The experiments show that the process is the first order with respect to the surface area, indicating that the detachment of EDTA complex from the surface is the responsible mechanism. (C) 1997 Academic Press.