Collect. Czech. Chem. Commun. 1992, 57, 2227-2234

Heats of Solution of Some Sodium and Potassium Salts in Water and in Water-Methanol Mixtures

Ján Benko and Oľga Vollárová

Department of Physical Chemistry, Comenius University, 842 15 Bratislava


The enthalpies of solution ∆Hs0 were determined for NaSCN, KSCN, NaBrO3, KBrO3, NaClO3, KClO3, NaIO4, KMnO4, KNO2 and NaNO2 in water-methanol mixtures. The transfer functions ∆Ht0 of the salts and anions were calculated based on the extrathermodynamic TPTB assumption. The ∆Ht0 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.