Study of interactions of l-aspartic acid and l-glutamic acid with some metal acetates through volumetric behaviour over the temperature range (288.15 to 318.15) K

Apparent molar volumes, V2,ϕ, of l-aspartic acid and l-glutamic acid have been determined in aqueous solutions of (0.1, 0.25, 0.5, and 1.0) mol · kg−1 of lithium acetate dihydrate, magnesium acetate tetrahydrate, and calcium acetate at T = (288.15, 298.15, 308.15, and 318.15) K by density measurements. The data have been used to calculate partial molar volume, V2∘, and transfer function, ΔtV∘, at infinite dilution from water to aqueous solutions of co-solutes by applying the correction due to ionisation of amino acids. Partial molar expansibilities, VE∘, hydration numbers, nH, and interaction coefficients of amino acids have also been determined. The dependence of above thermodynamic functions on concentration, temperature and nature of co-solute has been discussed in terms of various interactions taking place between hydrophobic and hydrophilic parts of amino acids and ions of co-solutes. Further, a comparison between present work and data reported in the literature for neutral amino acids dl-alanine, dl-α-amino-n-butyric acid and their corresponding hydroxy derivatives, l-serine and l-threonine in aqueous solutions of these co-solutes has been made.