Thermodynamic properties of aqueous-organic systems with low water contents. 2. Limiting partial molar volumes of D2O and H2O intert-butyl alcohol and 1,4-dioxane at 288.15?318.15 K

Abstract

The densities of dilute solutions of H2O and D2O in 1,4-dioxane and tert-BuOD have been measured in the interval 288.15–318.15 K with an error of 2·10−6 g/cm3. The limiting partial molar volumes of D2O and H2O in 1,4-dioxane andtert-butanol have been determined by using an original procedure; the changes in the partial molar volume of water due to H-D substitution in the water molecules have been calculated. The analysis of the temperature dependence of the partial volumes of the components of the binary mixtures H2O (D2O) + 1,4-dioxane and H2O (D2O) +tert-BuOH (tert-BuOD) showed on the basis of Maxwell's crossing equations that the addition of small amounts of water significantly alters the structure of the unary organic solvent. In the presence of trace amounts of water the expansibility of 1,4-dioxane increases and that oftert-butanol decreases.