Solvent structure. III. The dependence of partial molal volumes on internal pressure and solvent compressibility

Abstract

Partial molal volumes, V�, at 25�C were measured for sucrose, ascorbic acid and aspirin in the solvents water, formamide, N,N-dimethylformamide and methanol. The dependence of V� on solvent compressibility enabled an estimate to be made of the intrinsic volumes, Vint, of the dissolved non-electrolytes. Effective pressures, Pe, in aqueous electrolyte solutions were calculated from previously determined internal pressure data. Substitution of Pe into the Tait-Gibson equation yielded values of Ve, the volume contraction of water due to electrostriction, which agree well with values obtained by other methods.

Compressibility studies of aqueous and CCl4 solutions of 18-crown-6 at T=298.15K

“…Dack [43] as well as Hyne [44] have described the utility of this parameter to understand the liquid structure and the structure-making and structure-breaking effects due to solute in aqueous solutions [45]. The results for (dU/dV) T as depicted in figure 4 show that internal pressure increases with 18C6 mole fraction in water but remains more or less constant in CCl 4 solutions.…”

Effects of solvent and ionic medium on the kinetics of axial ligand substitution in vitamin B12. Part VI. Partial molar volumes of some cobalamin derivates

“…Furthermore, in both cases the solvent compressibility increases on going from water to the organic cosolvent @(H,O) = 0.46 X lo4 atm-', j3-(dioxane) = 0.6 X lo4 atm-' ; 1.08 X lo4 fl(acetonitrile) = atm-') [12]. An increase in solvent compressibility is expected to give a decrease in partial molar volume [ 121 , which is contrary to the increase of partial molar volume found for the acetonitrile-water mixtures.…”

Partial molar volumes of ethylene glycol and water in their mixtures

“…This may result from the following two main reasons. At first, the partial molar volume is governed by the solvent compressibility, as has been demonstrated byHamilton and Stokes (15) and Dack(16) experimentally and by French and Criss (17) on the basis of the scaled particle theory. The isothermal compression coefficients of water and ethylene glycol are comparable: 4.52 X 10"5 (6) and 3.72 X 10"5 bar1(14), respectively, which are about half the values for alcohols(18).…”