The precipitation of barium chromate from aqueous solution (with rapid mixing): Kinetics of the crystal growth

Abstract

AbstractThe kinetics of precipitation of barium chromate from well‐stirred aqueous solutions of initial solute concentrations C0 = 0.0001 to 0.0010 M (supersaturations 8 to 80) was studied at 25 °C by conductivity measurements and chemical analysis. Nucleation occurred during induction periods and regular crystal growth then took place onto the crystallites formed during the induction periods. The crystal growth was rate‐controlled, in this range, by the rate of deposition of metal salt ions onto the growing crystal surfaces. This rate, at any time, then depended on both the overall surface area (At) and on the residual excess solute concentration (ΔCt) in solution according to the relation, the growth rate expressed in terms of degree of crystallisation was then The rate constant (Kα) for the crystallisation of barium chromate at 25 °C was 1.5 106 sec−1 M−2.