Equilibrium in solutions of chromic acid

By the method of static ion exchange chromatography, the presence of CrO3 anions, with degree of polymerization of more than two in chromic acid solution, has been directly confirmed experimentally. The model of solution Cr(VI) suggested in this study takes into account the equilibrium between separate chromic acid anions, including polychromates, as well as the material balance of total and free acidity and acidity generation (or conjugation) at stages of titration of chromic acid by alkali. The solution of the system of material balance equations led to estimation of the overall forming constants of anions Cr3O10-2 and Cr4O13-2, equal to 127 +/- 13 and 43 +/- 4, respectively, when I (ionic strength) = 0.