Question

How can you prove that CO₂ is released on heating CaCO₃? 

(OR) 

When calcium carbonate is heated it releases certain gas. What is the gas that has been released? How do you identify that gas? Write the activity of this reaction.

Answer 1

1. Take a pinch of Calcium Carbonate (lime stone) in a boiling tube

2. Heat the boiling tube over the flame of spirit lamp or burner. 

3. Now take a burning matchstick near the mouth of delivery tube.

Heating of calcium carbonate and testing the gas evolved with burning matchstick

4. We can observe that the matchstick kept near the mouth of the boiling tube will be put off. 

5. In the above activity, on heating CaCO₃, it decomposes to Calcium oxide (CaO) and Carbon dioxide (CO₂).

Reaction :  

6. When a decomposition reaction is carried out by heating, it is called thermal decomposition reaction.