Molal volumes of K2SO4, K3Fe(CN)6, and K4Fe(CN)6in water and in solutions of NaCl

Pycnometric and dilatometric measurements have been made on solutions of K2SO4, K3Fe(CN)6, and K4Fe(CN)6 in water and in solutions 0.01442m, 0.03908m, 0.09044m of NaCl at 25°C. Deviations from the Debye—Huckel predictions even at very high dilutions are found for K2SO4 and K4Fe(CN)6. Some similarities are found with the predictions of the Mayer theory in the DHLL+B2 form, whereas the comparison is less favorable with the predictions of IPBE. As a general rule, when deviations from the Debye—Huckel theory are found in water solutions, the same kind of deviations are observed also in NaCl, even at very small concentrations of the multivalent electrolytes.