THERMAL-DECOMPOSITION REACTIONS AND KINETIC-PARAMETERS OF NITRITOBISMUTHATES(III)

Thermal studies have been carried out on nitritobismuthates(III) of the silver group having the general formula M2Ag[Bi(NO2)6] where M = Cs, Rb, K, and the sodium group having the formula M2Na[Bi(NO2)6] where M = Cs, Rb. Typical thermal curves, temperatures of the endothermic peaks and percentage weight loss, calculated from the TG curve, are shown. On the basis of the results of thermal and X-ray analysis the mechanisms of the thermal decomposition reaction were determined for nitritobismuthates(III). The thermal curves were used to calculate kinetic parameters, activation energy Ea and order of reaction n by Zsako's and Coats and Redfern's methods. A comparison of the thermal stabilities of the salts under study was made. Within the same group of nitritobismuthates(III), the activation energy and the decomposition temperatures of the salts increases when the difference between the radii of outer sphere cations increases. © 1979.