[en] The present research forms the first part of the series on the investigation of the ion exchange behaviour of ferrocyanide molybdate(FeMo) and zirconium phosphate(ZrP) in water-alcohol and water-dioxane media. Since the above exchangers are not available indigenously, they were synthesized following published methods. That the reported methods of synthesis yield products with reproducible characteristics, were checked. pH titration of these two preparations in aqueous media showed that FeMo is a stronger acid than ZrP, the former, moreover, in its Cs⁺ and Na⁺ forms commence dissolving at pH values close to 5 and 2 respectively, and are completely dissolved at pH values 7.5 and 2.85 respectively. Titration curves with ZrP further indicated that as the pH increases, there occurs a reversal in the order of arrangement of Na⁺ and Cs⁺ curves, which reversal is attributed to a corresponding reversal of selectivity. Finally, both the chemical analysis and pH titration of FeMo confirm the existence of 4 replaceable H⁺ ions corresponding to H₄Fe(CN)₆, a constituent of ferrocyanide molybdate, while those of ZrP are consistent with the empirical formula Zr(HPO₄)₂.4.5 H₂O, having two replaceable H⁺ ions. (auth.)