Kinetics of Dissolution of Dicalcium Phosphate Dihydrate Crystals

¹ Chemistry Department, State University of New York at Buffalo, Buffalo, New York 14214, USA

The dissolution of dicalcium phosphate dehydrate has been studied by following changes in the calcium, phosphate, and hydrogen ion concentrations when undersaturated solutions are inoculated with seed crystals of the salt. The rate of dissolution follows an equation of the first order with respect to concentration; this suggests a diffusion-controlled process and changes in the rate of stirring that have a considerable effect on the observed rate. Experiments have been made at 15, 25, and 37 C and the energy of activation corresponding to the dissolution process is 3.8 kcal mol^-1.