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Die Kinetik der Isotopenaustauschreaktion zwischen As(III) und As(V) in HCl (2‐l0m) und Reaktantenkonzentrationen zwischen 0,01 und 0,05m wird mit Hilfe radioaktiver Indizierung (76 As) im Temperaturbereich 50‐130°C untersucht.

IR spectral investigations on ammonium perchlorate (AP) in the presence of varying amounts of ammonium permanganate (APm) and 2% by weight of different rare earth oxide additives were made over the temperature range 25-290 ~ Heating and spectral scanning were done simultaneously and the peak intensity was presumed to be proportional to the amount of undeeomposed AP. Presence of 10% APm lowered the temperature of AP decomposition from 200 to I10 ~ and increased the rate by several folds. Mixed oxide produced as a result of deflagration of APm are considered catalyzing the process. In the presence of rare earth oxides additives, the NH + stretching peak intensity decreased considerably, the extent followed the trend Gd203 > MnO2 > Nd203 > Pr203 > Dy203 > Y203 > La203 > virgin AP. An electron transfer mechanism is envisaged to explain the results.Thermal stability of AP is known to be sensitive to the presence of additives [1][2][3]. Depending on their structure and chemical properties additives increase the decomposition and combustion rates and lower the ignition temperature. Solymosi and others [4] have investigated the catalytic effect of oxides on the isothermal decomposition of AP. Our data on the mixtures of AP + KBr/KC1 showed that the presence of KBr/KC1 influence the thermal characteristics of AP [5]. Systematic studies are presented here to understand the effect of different rare earth oxide additives and also of MnO2 and NH4MnO4 on the IR spectral peak intensities while heating was going on concurrently.

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