The limiting partial molar volume and apparent molar volume of glycylglycine in aqueous KCl solution at 298.15 and 308.15Â K

Apparent molar volumes VΦ of glycylglycine in aqueous KCl solutions have been obtained from densities at 298.15 and 308.15 K measured with a vibrating-tube densimeter. These data have been used to deduce partial molar volumes of transfer ΔtrsVΦ0 from water to different KCl-water mixtures. ΔtrsVΦ0 values are positive. This result arises from the interaction of KCl with the charged centers of glycylglycine. The results show that ΔtrsVΦ0 depends less on temperature. Hydration numbers are calculated from VΦ0 data and ΔtrsVΦ0 are interpreted in terms of various interactions.