Some physical properties of saturated, supersaturated and undersaturated aqueous potassium bichromate solutions

Abstract

The solubility of potassium bichromate In water and the density, viscosity, and refractive Index of saturated aqueous potassium bichromate solutions were determined between 20 and 60 °C. The apparent partial molal volume of the solute as a function of temperature and the dependence of the logarithm of solubility on reciprocal temperature show bends at about 40 °C. However, the temperature dependences of density, refractive Index, and viscosity of saturated solutions do not show any unusual behavior at this temperature. Density and refractive Index In undersaturated and supersaturated regions of the solutions saturated at particular temperatures are approximately linear functions of temperature around saturation points.

Measurement and Modeling of Refractive Indices for Multicomponent Chromium Compound Solutions

“…1. It can be seen that the present experimental values for the refractive indices are in good agreement with the values reported in the literature [14,15].…”

“…Their advanced commercial production, process planning, environmental, technological and process applications urgently require the basic data on refractive indices for the chromium trioxide, potassium chromate, and potassium dichromate in aqueous and mixed aqueous solutions [8][9][10][11][12][13]. Szewczyk et al have measured the refractive indices of an aqueous solution of potassium dichromate [14,15]. In this study, the refractive indices of quaternary mixtures of chromium trioxide + potassium chromate + potassium dichromate + water (CPDW) have been measured from 298.15-333.15 K. From the experimental measurements of refractive indices, a molecular thermodynamic model of refractive indices for aqueous solutions of chromium compounds is proposed, on the basis of the molecular model for solution structure and the equation for the excess enthalpy of a binary solution, previously suggested by the authors [16][17][18][19].…”

Density and Viscosity of Undersaturated, Saturated, and Supersaturated Aqueous Ammonium Oxalate Solutions from 287 K to 325 K

“…Data on the physical properties of concentrated aqueous solutions of various compounds are useful in monitoring a crystal growth run and provide information about the nature of entities (ions, molecules, or large clusters) involved during growth (Mullin, 1972;Sangwal, 1994;Fredericks et al, 1994). However, the available experimental data mainly deal with low concentrations (Szewczyk et al, 1988;So ¨hnel and Novotny, 1985;So ¨hnel et al, 1984), and data for superaturated solutions are sparse (Khamskii, 1975;Szewczyk et al, 1985).…”

Densities and Viscosities of Chromium Trioxide + Potassium Chromate + Potassium Dichromate + Water from (298.15 to 333.15) K

“…It can be seen that our experimental values of densities and viscosities are in good agreement with those reported in the literature. 11 &-; 13,19…”

“…Hartford et al 12 have measured densities at T ) (15.6 to 50) °C and viscosities at T ) (25, 40, and 75) °C for both potassium dichromate aqueous solution and potassium chromate aqueous solution, respectively. Szewczyk et al 13 and Postnikov 14 have measured densities and viscosities for saturated potassium dichromate aqueous solution at T ) (21.15 to 60.2) °C and T ) (20 to 80) °C, respectively. Kudryashov et al 15 have measured densities for the potassium chromate + potassium dichromate + water system at T ) (25, 50, and 75) °C.…”