Activity coefficients for NaCl–monosaccharide ( d-glucose, d-galactose, d-xylose, d-arabinose)–water systems at 298.15 K

Electrochemical cells with a sodium ion selectivity electrode (Na–ISE) versus a chloride ion selectivity electrode (Cl–ISE) as a reference electrode were used to determine the activity coefficients for NaCl–monosaccharide ( d-glucose, d-galactose, d-xylose, and d-arabinose) systems in water at 298.15 K. A comparison of the results thus obtained was made with those determined by another electromotive force (emf) method. It is shown that agreement is excellent. The Gibbs free energy parameters of the interactions between these sugars and NaCl in water were evaluated together with the parameter C 1(CHOH, exo), indicating the interaction of the exocyclic CHOH group of saccharide molecules and NaCl. The results suggested that the interactions of these monosaccharides with NaCl are controlled mostly by the dominant conformer of their molecules in water.