Potentiometric study of the interaction of Cr3+ and O2− ions in fused NaCl–2CsCl eutectic

The physical and chemical properties of chromium chlorides have been studied in fused NaCl–2CsCl eutectic at the temperature range 843–1008 K using an electrochemical cell containing a platinum-oxygen electrode with solid electrolyte membrane, which was used as pO2− indicator electrode. The concentration of oxygen ions in the solution was modifying by dropping the calculated amount of BaO. Titration of Cr3+ chlorocomplex by O2− ions demonstrated the precipitation of CrOCl and Cr2O3. The solubility constants of these compounds were calculated. E–pO2− and three-dimensional E–pO2−–T type diagrams, which summarized the properties of chromium species in the melt, were determined.