Studies of the Hydrous Titanium Oxide Ion Exchanger. II. The Equivalence of the Exchange Adsorption of Cations and the Dissociation Constant

In order to elucidate the fundamental properties of hydrous titanium oxide as a cation exchanger, the authors examined the stoichiometry of cation exchange and the acid-base property of the exchanger by means of titration curves. The results may be summarized as follows: 1. The equivalent exchange between the hydrogen ion and either the sodium or strontium ion holds over a wide range of conditions, such as the pH, the ionic strength, and the particle size of the exchanger. 2. The method of conditioning for obtaining the exchanger in the pure hydrogen form has been established. 3. The water content in the exchanger depends on the ionic composition. 4. This hydrous titanium oxide is a four-functional, weakly acidic cation exchanger and has the following apparent pK values: pK1 6.7±0.1, pK2 10.3±0.2, pK3 12.3±0.2, and pK4 13.2±0.2. The corresponding apparent ion exchange capacities are 2.2±0.1, 1.2±0.2, 0.7±0.3, and 0.2±0.3 meq. Na+/g respectively.