Densities and speed of sound of glycine in concentrated aqueous NaBr, KCl, KBr andMgCl2 at T=298.15 K

The density and speed of sound of glycine (up to 3 mol . kg(-1)) in aqueous concentrated NaBr, KCl, KBr and MgCl2 (up to 4 mol . kg(-1)) at T = 298.15 K have been measured and the apparent molar volumes and compressibilities calculated therefrom. The compound MgCl2 influences the apparent molar and transfer properties of the volumes and compressibilities more strongly than any other 1:1 electrolyte studied here. The apparent molar properties of glycine can be successfully correlated with the concentration of the electrolyte using two parameters lambda' and lambda" representing the binary and ternary interactions among the glycine and electrolytes. These parameters, when employed in a Pitzer-type equation allow the calculation of both volumes and compressibilities of electrolytes. The importance of the parameters involved is discussed in terms of the ionic interactions present in these systems. (C) 2003 Elsevier Science Ltd. All rights reserved.