Question

Carbon dioxide is obtained by heating :
(a) Barium Carbonate
(b) Potassium Carbonate
(c) Sodium Carbonate
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Answer 1

Explanation:

calcium carbonate is the correct answer

but this is not in option

Answer 2

Carbon dioxide gas is produced by heating a)Barium Carbonate and B) Potassium Carbonate as well as c) Sodium carbonate.

Thermal decomposition

• The thermal decomposition of a compound breaks it down into separate constituents.  All alkali metals evolve C$O_{2}$ on thermal decompositions.

• The thermal decomposition of Barium carbonate gives Barium oxide and Carbon dioxide. The reaction is as follows:

              BaC$O_{3}$    →  BaO + C$O_{2}$

• Decomposition of Potassium carbonate on heating gives potassium oxide and C$O_{2}$ . The reaction is:

               $K_{2}CO_{3}$ → $K_{2} O$ + C$O_{2}$

• C$O_{2}$ gas also evolves on heating anhydrous sodium carbonate. The reaction to be followed is:

                 $Na_{2}CO_{3}$ → $Na_{2} O$ + C$O_{2}$