Question

Why is carbon dioxide gas used to extinguish fire?

Answer 1

Hint: Carbon dioxide removes one of the elements of the fire triangle. There are three elements in the fire triangle, fuel, oxygen and heat. Fire will sustain when all the three elements are present together. If one or more of the elements is removed, fire will stop.

Complete answer:
Carbon dioxide gas is non inflammable. Carbon dioxide gas does not support combustion.
It displaces oxygen so that oxygen cannot come in contact with fire. Thus, carbon dioxide gas stops the supply of oxygen thereby removing oxygen from the fire triangle.
In fire extinguishers, carbon dioxide gas is stored under very high pressure. When carbon dioxide gas comes out of fire extinguishers, it is very cold. So it cools the fuel.
To extinguish fire, carbon dioxide gas is frequently used in laboratories and kitchens.

Additional Information Different types of fire extinguishers are water and foam, carbon dioxide, dry chemical, wet chemical, clean agent, dry powder and water mist

Note: In the fire triangle, three elements are fuel, air and heat. Fuel is something that can burn. If all the fuel is consumed, and no more fuel is left, the fire will stop. Air provides oxygen. Oxygen is necessary for the combustion. If oxygen supply is removed, fire will stop. Heat source ignites the fuel. If no heat source is present, the fire will not generate, even if oxygen and fuel are present.