Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

We determined apparent molar volumes V/ at 298.15 6 (T/K) 6 368.15 and apparent molar heat capacities Cp,/ at 298.15 6 (T/K) 6 393.15 for aqueous solutions of HIO3 at molalities m from (0.015 to 1.0) mol Ae kg 1, and of aqueous KIO3 at molalities m from (0.01 to 0.2) mol Ae kg 1 at p = 0.35 MPa. We also determined V/ at the same p and at 298.15 6 (T/K) 6 368.15 for aqueous solutions of KI at m from (0.015 to 7.5) mol Ae kg 1. We determined Cp,/ at the same p and at 298.15 6 (T/K) 6 393.15 for aqueous solutions of KI at m from (0.015 to 5.5) mol Ae kg 1, and for aqueous solutions of NaIO3 at m from (0.02 to 0.15) mol Ae kg 1. Values of V/ were determined from densities measured with a vibrating-tube densimeter, and values of Cp,/ were determined with a twin fixed-cell, differential temperature-scanning calorimeter. Empirical functions of m and T were fitted to our results for each compound. Values of Ka, DrHm, and DrCp,m for the proton ionization reaction of aqueous HIO3 are calculated and discussed.