The kinetics of the precipitation and crystal growth of dicalcium phosphate dihydrate (DCPD) was followed in 0.15 M sodium chloride solutions at constant pH (pH = 5.0) and temperature (25o C). Precipitations were performed from equimolar solutions of calcium chloride and sodium phosphate prepared by direct mixing of the reactants. The amount of precipitate formed (X moles per 1) was calculated from the quantity of sodium hydroxide added by a pH-stat device. The system is of physiological interest, because precipitation of DCPD may play an important role during dental caries formatio
