Question

Why is soda-acid fire extinguisher used?

Answer 1

This type of fire extinguisher contains a bottle of sulphuric acid supported by a metallic container filled with baking soda solution. When the cylinder is inverted and knob struck, against the ground, the acid bottle breaks and the acid comes in the contact with the baking soda.
\(2NaHCO_3 + H_2SO_4 \rightarrow Na_2SO_4 + 2H_2O + 2CO_2\)
As a result carbon dioxide is liberated. This increases the percentage of carbon dioxide in the air. Due to this, the supply of air is cut off and therefore, fire is extinguished. These types of extinguishers are used in cinema halls, multistorey buildings, etc.