Interactions in l-histidine/l-glutamic acid/l-tryptophan/glycylglycine + 2 mol L−1 aqueous KCl/KNO3 systems at different temperatures: An isothermal compressibility study

Measured values of ultrasonic velocity and density have been used to calculate the isothermal compressibilities (κT) of l-histidine/l-glutamic acid/l-tryptophan/glycylglycine + 2 mol L−1 aqueous KCl/KNO3 systems as a function of amino acid/di-peptide molal concentration and at temperatures in the range of 298.15–323.15 K. The trends of variations of κT, on successive addition of amino acid/di-peptide amount to solutions and on increase in temperature have been discussed in terms of solute–solute and solute–solvent interactions operative in the studied systems as well as difference in interactions with KCl/KNO3 at same concentration have been shown.