Thermodynamic Properties of K2U4O12(s) and K2U4O13(s) by EMF and Calorimetric Measurements

✍ Scribed by V.S. Iyer; K. Jayanthi; V. Venugopal

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 267 KB
• Volume: 132
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1997.7472

✦ Synopsis

The coexistence of K 2 U 4 O 12 (s) and K 2 U 4 O 13 (s) in the K-U-O system up to 1200 K was established. The EMF measurements over the above phase field were carried out using a calciastabilized zirconia solid electrolyte galvanic cell in the temperature range 1053 to 1222 K. The equilibrium oxygen partial pressure above the phase fields was calculated to be ln p(O 2 ) kPa ؎ 0.09 ‫/25413؊؍‬T ؉ 25.065. The enthalpy increment values of K 2 U 4 O 12 (s) and K 2 U 4 O 13 (s) were measured using a high temperature Calvet calorimeter by drop method and the thermodynamic values were suggested for the compounds.