Apparent molar volumes and apparent molar heat capacities of aqueous KI, HIO3, NaIO3, and KIO3 at temperatures from 278.15 K to 393.15 K and at the pressure 0.35 MPa

We determined apparent molar volumes Vϕ at 298.15 ⩽ (T/K) ⩽ 368.15 and apparent molar heat capacities Cp,ϕ at 298.15 ⩽ (T/K) ⩽ 393.15 for aqueous solutions of HIO3 at molalities m from (0.015 to 1.0) mol · kg−1, and of aqueous KIO3 at molalities m from (0.01 to 0.2) mol · kg−1 at p = 0.35 MPa. We also determined Vϕ at the same p and at 298.15 ⩽ (T/K) ⩽ 368.15 for aqueous solutions of KI at m from (0.015 to 7.5) mol · kg−1. We determined Cp,ϕ at the same p and at 298.15 ⩽ (T/K) ⩽ 393.15 for aqueous solutions of KI at m from (0.015 to 5.5) mol · kg−1, and for aqueous solutions of NaIO3 at m from (0.02 to 0.15) mol · kg−1. Values of Vϕ were determined from densities measured with a vibrating-tube densimeter, and values of Cp,ϕ 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, ΔrHm, and ΔrCp,m for the proton ionization reaction of aqueous HIO3 are calculated and discussed.