THERMAL DECOMPOSITION OF OXALATES OF LANTHANUM AND THORIUM IN VACUUM.

Thermal decomposition of hydrated oxalates of lanthanum and thorium has been studied in vacuum in two ways : (a) heating the same sample to higher temperatures progressively and collecting the gaseous product in the specified temperature range and analysing and (b) taking different samples each time heated to the predetermined temperature, collecting the gaseous product as well as the solid_residue and analysing them. The gaseous product contained carbon monoxide and carbon dioxide. The residue contained any undecomposed oxalate, basic carbonate of the metal or its oxide and elemental carbon. A mechanism for the  decomposition is suggested on the basis of the intermediate formation of a metallic carbonate.