Question

Write short notes on the fire extinguisher.

Answer 1

Hint : We know that the soda-acid fire extinguisher contains sulphuric acid and a solution of sodium hydrogen carbonate. The reaction between sodium bicarbonate and sulphuric acid produces sodium carbonate, water and carbon dioxide.

Complete Step By Step Answer:
Soda acid type extinguishers act by cutting off supply of air. It acts on all types of fire except due to electrical and inflammable liquids. The carbon dioxide is liberated by the action of acid on baking soda. It increases the percentage of carbon dioxide in air ( $ CO $ is non-supporter of combustion). This type of fire extinguisher contains a bottle of sulphuric acid supported by a metallic container filled with a baking soda solution. When the cylinder is inverted and the knob is struck, against the ground, the acid bottle breaks and the acid comes into contact with the backing soda. The fire extinguisher extinguishes the fire in three ways:
-The fire extinguisher extinguishes the fire by cutting the supply of air.
-The fire extinguisher extinguishes the fire by cooling the combustible substance.
-The fire extinguisher extinguishes the fire by cutting the supply of air while simultaneously cooling the combustible substance.
Soda-acid fire extinguishers contain sulphuric acid supported on a metallic base with a solution of sodium hydrogen carbonate (baking soda) in a container. Both remain separated before the use. The fire extinguisher is an active fire protection device used to extinguish or control small fires, often in emergency situations. Fire extinguishers contain different chemicals, depending on the application. Handheld extinguishers, which are commonly sold at hardware stores for use in the kitchen or garage, are pressurized with nitrogen or carbon dioxide $ \left( C{{O}_{2}} \right) $ to propel a stream of a fire-squelching agent to the fire. The active material may be a powder such as potassium bicarbonate $ \left( KHC{{O}_{3}} \right), $ liquid water, and evaporating fluorocarbon, or the propelling agent itself.

Additional Information:
The Soda-acid fire extinguisher is an example of a carbon dioxide type fire extinguisher. Foam fire extinguisher shows the cooling effect. The foam creates a barrier between the fire and burning fuel. Any fire extinguisher does not remove the combustible substance. They only decrease the cools of the burning substance. When the cylinder is used as a knob struck at the ground, the sulphuric acid comes into contact with baking soda, the reaction between both taking place and releasing a carbon dioxide gas.

Note :
Remember that as a result carbon dioxide is liberated. This increases the percentage of carbon dioxide in air. Due to this the supply of air is cut off and there, fire is extinguished. These types of extinguishers are used in cinema halls, multistorey buildings, etc.