SOLUBILITY AND PHYSICOCHEMICAL PROPERTIES OF SATURATED SOLUTIONS IN CESIUM MOLYBDATE – ISOBUTYL ALCOHOL – WATER SYSTEM AT 25 °C

Abstract

The solubility in the Cs2MoO4 – iso-C4H9OH – H2O system at 25 °C was studied for the first time. It is shown that in this system no formation of new compounds occurs. Isobutyl alcohol has limited solubility in water. This is confirmed by the fact that when cesium molybdate is added to the system, the mutual solubility of isobutyl alcohol and water decreases significantly. In the lower aqueous layer the solubility of C4H9OH in water is from 8.13 wt.%, in pure water to 0.04 wt.% of C4H9OH in a saturated 79.91% aqueous solution of Cs2MoO4; in the upper alcohol layer the solubility of water in isobutyl alcohol decreases from 16.90 to 0.51 wt.% of H2O in the presence of 0.0069 wt.% of Cs2MoO4. In the nonvariant state the saturated liquid phases (L1 and L2), which are in equilibrium with the solid phase of Cs2MoO4, have the composition (wt.%): L1 – 79.58 Cs2MoO4, 0.04 C4H9OH and 20.38 H2O; L2 – 0.069 Cs2MoO4, 99.48 C4H9OH and 0.51 H2O. Stratification is observed throughout the concentration range. In this system there is neither upper nor lower critical point of solubility and there is no binoidal solubility surface of the ternary system. Only two open sections of this surface appear which are displayed as two isolated curves on the projections of the spatial diagram. The density, refractive index, and dynamic viscosity of saturated solutions of the system were determined, and the isotherms of specific and molar volumes were calculated. The results of the study of physico-chemical properties of this system of saturated solutions show a regular change of all properties of conjugate liquid phases in accordance with the changes in their composition and character of interaction of components in the system.