Volumetric properties of aqueous 2-chloroethanol solutions and volumes of transfer of some amino acids and peptides from water to aqueous 2-chloroethanol solutions

Abstract

Densities and apparent molar volumes of aqueous 2-chloroethanol were determined at temperatures from 15.0 to 34.4degreesC using digital densimetry. The results of the volumetric measurements have been used to calculate the following thermodynamic quantites at 25degreesC:V-o(2)= 55.05+/-0.02 cm(3)-mol(-1), (partial derivativeV(2)(o)/partial derivativeT)(p)=0.01486+/-0.00318 cm(3)-K-1-mol(-1), and (partial derivative(2)V(2)(o)/partial derivativeT(2))(p)=0.02972+/-0.00318 cm(3)-K-2-mol(-1). Partial molar volumes of transfer from water to 1 mol-dm(-3) 2-chloroethanol have also been determined for L-glycine, L-alanine, L-serine, L-glutamic acid, and L-aspartic acid at 35.0degreesC. The transfer results have been explained in terms of the nature of the interactions of the groups in the solute and solvent. Hydration numbers of L-glycine and L-alanine have also been calculated in aqueous 2-chloroethanol.