Solubility and metastable zone width (MSZW) of aqueous sodium dichromate solutions in different concentration of sodium chromate were studied experimentally by the polythermal method using a turbidity monitoring technique. The effects of cooling rate R, saturation temperature T-o of sodium dichromate and concentration c(i) of sodium chromate on the MSZW were studied. The results show that the MSZW widens with increasing cooling rate R but it narrows with increasing saturation temperature To of sodium dichromate and concentration c(i) of sodium chromate. The experimental data were analyzed by using an equation, based on the classical three-dimensional nucleation theory, relating MSZW with cooling rate R. (C) 2016 Elsevier B.V. All rights reserved.