Volumetric Properties of Some α,ω-Aminocarboxylic Acids in Aqueous Sodium Acetate and Magnesium Acetate Solutions at T = (288.15 to 318.15) K

Abstract

Densities, ρ, of glycine (GLY), 4-aminobutyric acid (4-ABA), and 6-aminocaproic acid (6-ACA) in water and in aqueous solutions of sodium acetate (SA) and magnesium acetate (MA) having a molality of (0.10, 0.25, 0.50 and 1.00) mol·kg−1 have been determined by using a vibrating-tube digital densimeter at T = (288.15 to 318.15) K. These data have been used to calculate the apparent molar volumes, Vϕ, of the studied α,ω-aminocarboxylic acids. The partial molar volumes, V2,m0, at infinite dilution are evaluated and further used to obtain the corresponding transfer volumes, ΔtrV2,m0, for α,ω-aminocarboxylic acids from water to aqueous SA and MA solutions. Partial molar expansibilities, VE0, of α,ω-aminocarboxylic acids and interaction coefficients have been calculated. The ΔtrV2,m0 values for the α,ω-aminocarboxylic acids are positive, and these values increase with an increase in the concentration of SA and MA as well as with temperature. The results obtained have been rationalized in terms of various interactions taking place in these solutions.