Carbon dioxide is used as a fire extinguisher.

Ans.

1. Carbon dioxide is not combustible and does not support combustion.
2. When it spread on a burning object, it covers the object and separates it from air. Without air (i.e. oxygen) the fire is extinguished.
3. It is heavier than air as well as non poisonous.
4. Hence, Carbon dioxide is used as a fire extinguisher.