Thermal decomposition of oxalates: Part XXIV. Effect of the sample preparation and environmental atmosphere on the thermal stability of silver oxalate

Abstract

The thermal decomposition of silver oxalate has been studied using mechanism-dependent and mechanism-independent isothermal kinetics, conventional rising temperature thermogravimetry (TG) and a TG computer program. Studies were carried out on four different preparations of the sample which involved precipitation from stoichiometric and non-stoichiometric conditions. Each sample was studied under atmospheres of nitrogen, air, oxygen, and carbon dioxide as well as under vacuum. The assignment of stability information based on the magnitude of the Arrhenius parameters is shown to be deceptive. Applying the computer program and the limiting kinetic condition of α → 0 allows the relative stability of various preparations and the retarding influence of oxygen and carbon dioxide, to be quantitatively evaluated.