Volumetric properties of aqueous solutions of polyols between 0.5 and 25 °C

Abstract

The volumetric properties of aqueous solutions containing non-electrolytes have been determined by density measurements in the temperature range 0.5-25 "C. Linear polyols CH,OH(CHOH),CH,OH with n = 2-4 (n = 4 has three diasteroisomers), myo-inositol and t-butylurea have been studied.Vz and the coefficients of the virial expansion of the excess property (V,,, V,,, . . .) have been evaluated and interpreted in terms of solute-solute and solute-solvent interactions with the aid of the enthalpy and free-energy data where known. The theory of group contributions has been used to interpret the V,, values of those linear polyols not exhibiting solute-solute interactions at 25°C. The results confirm the relation between the signs of the enthalpic and volumetric contributions also found for other kinds of non-electrolyte.

Modulation in physico-chemical characteristics of some polyhydroxy solutes in presence of l-glycine: Volumetric and NMR spectroscopic approach

“…The V 2° values of solutes studied in water are in good agreement with the literature (Table 3) values [4,6,11,13,[18][19][20][21][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44]. The standard partial molar volumes of transfer at infinite-dilution,  tr V 2 º of each solute from water to aqueous L-glycine solutions were calculated as:…”

“…We have studied thermodynamic and transport properties of various saccharides, their derivatives, and polyols and their interactions with electrolytes in aqueous media [18,19]. To understand the physico-chemical characterstics of polyhydroxy solutes and how solute-solvent interactions get modified in the presence of amino acids, we have carried out densimetric and 1 H and 13 C NMR based spectroscopic studies.…”

“…Sorbitol is widely used as a stabilizing agent in the food industry as well as in pharmaceutical formulations since it is harmless upon ingestion. Myo-inositol is a cyclic polyol and it is an essential nutrient for most living cells including protozoa [9][10][11][12][13][14][15][16]. Disaccharides are well known for their ability to preserve life in cells, organisms, and biomolecules against environmental stresses.…”

Apparent Molar Volume and Expansibilityof Cyclohexanol in Benzene and Cyclohexane Solutions

“…Since at in®nite dilution only solute-solvent interactions can exist, V 2Y0 can therefore provide evidence about the effect of the solute on the structure of the solvent. V 2Y0 may be assumed to result from the sum of two contributions: the intrinsic volume of the non-solvated solute molecule and a term which takes into account the volume changes undergone by the solvent molecules during the solvation process [19]. Since the water-alcohol hydrogen bond is generally stronger than the alcohol-alcohol bond [20], the introduction of cyclohexanol into water may break down self-association in the alcohol, and a new hydrogen bond will be formed between the alcohol and water molecules.…”

“…According to the solvation model proposed by Wurzburger et al [19], the v 22 values represent the volume changes brought about by the process in which two solvated solute molecules move from in®nite distance to proximity. Thereby, the overlap of two solvated cospheres of solvated molecules makes the volume change negative when solvent is released from a cosphere which is more structured than Units: a cm 3 Ámol À1 , b cm 3 ÁkgÁmol À2 ; c Ref.…”