Volumetric behavior of the DL-valine in aqueous solutions of sodium nitrate at different temperatures

Abstract

Densities of DL-valine (2-amino-3-methylbutanoic acid) in aqueous solutions of sodium nitrate were determined at temperatures ranging from 283.15 to 318.15 K using an Anton Paar DMA 5000 vibrating tube densitometer. The apparent molar volume, infinite dilution apparent molar volume, second derivative of the infinite dilution partial molar volume with respect to temperature, partial molar volume of transfer at infinite dilution and the number of hydration were calculated. The results obtained were discussed in terms of the dominant interactions in solution, it was found that the DL-valine has a disruptor effect in the structure of the solvent and that at infinite dilution solute-solvent interactions are dominant between isopropyl group the amino acid and sodium and nitrate ions.