Solubility of chromium(III) tris-acetylacetonate [Cr(C5H7O2)3] in different media

Chromium(III) tris-acetylacetonate solubilities in water and isopropanol at temperatures from 10 to 60°C, in aqueous alkali metal chloride solutions and HCl with concentrations from 0 to 3.6 mol/l for the salts and from 0to 6 mol/l for HCl at 25°C, and in mixed water-ethanol and water-isopropanol solutions at different contents of the organic component have been studied. At the temperatures studied, the logarithm of the [Cr(acac) 3 ] solubility in water and isopropanol has been shown to vary linearly with inverse temperature. The enthalpy and entropy changes in [Cr(acac) 3 ] dissolution in water (ΔH 0 and ΔS > 0) have been calculated. The solubility logarithm versus salt concentration obeyed the Sechenov equation. In the HCl solutions salting-in of the nonelectrolyte with the growing content of HCl has been observed. The solubility in the mixed solvents first increased (to 0.2-0.3 mole fractions) and then was little dependent on the organic component content.