Question

The gas produced on heating CaCO₃ is

• A. O₂
• B. CO₂
• C. CO
• D. O₃

Answer 1

The correct option is B

CO₂

• Decomposition reaction is a chemical reaction in which one reactant decomposes to form two or more products.
• The decomposition reactions take place in the presence of heat, light, or electricity.
• The chemical reaction which takes place in presence of heat is called a thermal decomposition reaction.
• The decomposition reaction taking place in presence of sunlight is called photolysis.
• The decomposition reaction which takes place in presence of electricity is called electrolysis.

Explanation for correct answer

• The decomposition of Calcium carbonate is a thermal decomposition reaction.
• Calcium carbonate (CaCO₃) breaks into Calcium oxide (CaO) and Carbon dioxide(CO₂).
• CaCO₃(s)$\stackrel{\mathrm{Heat}}{\to }$CaO (s)+ CO₂(g)