Question

For the decomposition of the anhydrous calcium oxalate, which of the following steps occur?

(a) Intermediates, transition state, product

(b) Intermediates, anhydrous oxalate, calcium oxysalts

(c) Intermediates, aqueous hydrates, calcium hydroxides

(d) Intermediates, anhydrous calcium oxalate, calcium carbonate

The question was posed to me in an interview.

My question is from Applications of DTA and TGA in chapter Thermal Analysis of Solid State Chemistry

Answer 1

Right choice is (d) Intermediates, anhydrous calcium oxalate, calcium carbonate

Best explanation: In the multistage decomposition processes, TG either alone or in conjunction with DTA may be used to separate and determine the individual steps. A known example is the decomposition of the anhydrous calcium oxalate where the decomposition occurs in three steps, intermediates, anhydrous calcium oxalate, and calcium carbonate.