화학공학소재연구정보센터
Journal of Chemical and Engineering Data, Vol.54, No.8, 2251-2255, 2009
Enthalpies of Dilution of N-Glycylglycine in Aqueous Sodium Chloride and Potassium Chloride Solutions at 298.15 K
The enthalpies of dilution of N-glycylglycine in aqueous sodium chloride and potassium chloride solutions have been determined by using flow microcalorimetry at 298.15 K. The homogeneous enthalpic interaction coefficients (h(2), h(3), h(4)) in the range of sodium chloride and potassium chloride molality, (0 to 0.6) mol.kg(-1), have been calculated according to the McMillan-Mayer theory. It shows that the enthalpic pairwise interaction coefficients h(2) of N-glycylglycine in both electrolyte solutions are negative, and the value of h(2) in aqueous sodium chloride solutions is less than that in aqueous potassium chloride solutions of the same molality. The values of h, for N-glycylglycine in aqueous solutions of sodium chloride pass through a minimum at about 0.10 mol.kg(-1), while the corresponding values of h(2) in aqueous potassium chloride solutions become less negative with an increase in the molality of potassium chloride. The results are discussed in terms of the solute-solute and solute-solvent interactions.