Thermodynamics of the interaction of HCl with D-xylose in water at 278.15-318.15 K

The thermodynamic parameters of interaction of HCl with D-xylose in water were determined from electromotive force measurements from 278.15 to 318.15 K. The correlation between the pair interaction Gibbs free energy parameters for HCl-sugar (gHCl-S) and the mean number (n(e-OH)) of equatorial hydroxy groups in sugar molecules was found to be gHCl-S/J kg mol-2 = (41.2 ± 2.1) + (16.88 ± 0.52)n(e-OH). Refractive indices of aqueous D-xylose solutions were measured and used to evaluate the polarizability of D-xylose molecule in water. Several theoretical models were used to calculate the salting constant of D-xylose. The results show that the calculated values are reasonably in agreement with the experimental ones.Key words: thermodynamics, HCl, D-xylose, interaction parameter, salting constant.