Abstract
The specific conductivity of saturated aqueous solutions of KH2PO4 and its solubility are investigated in the pH range between 2.5 and 6.3. It is found that the values of specific conductivity and solubility show minima at pH of about 3.5 and 4, respectively. These observations are discussed in terms of the presence of a variety of species of different concentrations in saturated solutions of different pH. The conductivity data reveal that the solutions are highly associated. The presence of species other than H2PO4 and K+ explains the experimentally observed deterioration in the quality of KDP crystals from solutions of pH deviating from the natural value.