Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

The density of glycine, l-alanine, and l-serine in formamide water mixtures was measured at 298.15 K and used to calculate the apparent molar volume V and limiting partial molar volume Vdeg of the amino acids. Transfer partial molar volume ?trVdeg from water to formamide water mixtures and the volumetric interaction coefficients were also obtained to interpret the solute solvent interaction. Values of ?trVdeg of the three amino acids were all positive and increased with increasing formamide concentration in the mixtures, in the order of l-alanine less than glycine less than l-serine, which was consistent with the cosphere overlap model. The interaction of formamide molecules decreased its structural-breaking effect and consequent interaction with amino acids, leading to negative triplet interaction coefficients.