HEATS OF SOLUTION OF SOME SODIUM AND POTASSIUM-SALTS IN WATER AND IN WATER-METHANOL MIXTURES

The enthalpies of solution DELTAH(s)0 were determined for NaSCN, KSCN, NaBrO3, KBrO3, NaClO3, KClO3, NalO4, KMnO4, KNO2 and NaNO2 in water-methanol mixtures. The transfer functions DELTAH(t)0 of the salts and anions were calculated based on the extrathermodynamic TPTB assumption. The DELTAH(t)0 values of the anion obtained from the sodium and potassium salts were compared. The differences observed, particularly at higher concentrations of the cosolvent, are discussed with respect to the interactions between the solvent molecules and the solute-solvent interactions.