EFFECT OF NONELECTROLYTE PROPERTIES ON THE ENTHALPIC INTERACTION COEFFICIENTS FOR NACL/NAI-NON-ELECTROLYTE PAIRS IN WATER - DISSOLUTION ENTHALPIES OF NACL AND NAI IN AQUEOUS-SOLUTIONS OF BUTANE-2-ONE AND 1,2-DIMETHOXYETHANE AT 25-DEGREES-C

Dissolution enthalpies of NaCl and Nal in aqueous solutions of butan-2-one and 1,2-dimethoxyethane have been measured and appropriate enthalpic pair interaction coefficients, h(xy)(electrolyte-non-electrolyte) in water have been determined. These results along with the other data concerning the NaCl-non-electrolyte and Nal-non-electrolyte pairs taken from our earlier reports and from the literature, were analysed with respect to the effect of the non-electrolyte properties on variations of the h(xy) values in water. The h(xy) coefficients for both NaCl-non-electrolyte and Nal-non-electrolyte systems are linearly correlated with the heat capacity of the non-electrolyte interaction with solvent water. The group contributions illustrating the interactions between the electrolyte (NaCl or Nal) and CH2, OH, O, CO, 'Pep' and 'iPep' groups in the non-electrolyte molecules were calculated and discussed from the viewpoint of a competition between the solute-solute and solute-solvent interactions. The analysed enthalpic pair interaction coefficients are well correlated through the multiparameter equation of the Abraham-Kamlet-Taft type.