Transfer Partial Molar Isentropic Compressibilities of (l-Alanine/l-Glutamine/Glycylglycine) from Water to 0.512 ${\mathrm{mol}}\!\cdot \!{\mathrm{kg}}^{-1}$ Aqueous ${\mathrm{KNO}}_{3}/0.512\, {\mathrm{mol}}\!\cdot \! {\mathrm{kg}}^{-1}$ Aqueous ${\mathrm{K}}_{2}{\mathrm{SO}}_{4}$ Solutions Between 298.15 K and 323.15 K

Abstract

Speeds of sound of (l-alanine/l-glutamine/glycylglycine $\,+\, 0.512\, {\mathrm{mol}}\cdot {\mathrm{kg}}^{-1}$ aqueous ${\mathrm{KNO}}_{3}/0.512\, {\mathrm{mol}}\cdot {\mathrm{kg}}^{-1}$ aqueous ${\mathrm{K}}_{2}{\mathrm{SO}}_{4}$) systems have been measured for several molal concentrations of amino acid/peptide at different temperatures: $T$= (298.15 to 323.15) K. Using the speed-of-sound and density data, the parameters, partial molar isentropic compressibilities $\phi _{\kappa }^{0}$ and transfer partial molar isentropic compressibilities $\Delta _{\mathrm{tr}} \phi _{\kappa }^{0}$, have been computed. The trends of variation of $\phi _{\kappa }^{0}$ and $\Delta _{\mathrm{tr}} \phi _{\kappa }^{0}$ with changes in molal concentration of the solute and temperature have been discussed in terms of zwitterion–ion, zwitterion–water dipole, ion–water dipole, and ion–ion interactions operative in the systems.