Volumetric, viscometric and refractive index study of amino acids in mixed solvents at 308.15 K

Abstract

Densities, ρ, viscosities, η and refractive indices n D for solutions of (0.10, 0.20, 0.30, 0.40 and 0.50 M) glycine (Gly), DL-alanine (Ala) and L-serine (Ser) in aqueous 1-propanol (10 and 30% v/v) at 308.15 K have been determined. These data have been used to calculate apparent molar volumes, φv, partial molar volumes, and Falkenhagen and Jones–Dole coefficients, A and B, respectively. Free energies of activation of viscous flow, and per mole of solvent and solute, respectively, were obtained by using transition state theory to the B-coefficient data. The molar refractive indices, R D were calculated from the experimental values of refractive indices for all the three amino acids + aqueous 1-propanol ternary mixtures. These parameters were used to discuss the solute–solute and solute–solvent interactions and also the effect of cosolvent (1-propanol) on these interactions.