Question

Sodium hydrogen carbonate is used in fire extinguishers.
A) True
B) False

Answer 1

HINT: Sodium hydrogen carbonate is a weak base and when reacted with acid liberates carbon dioxide. Carbon dioxide is a colorless gas which puts off the light (fire) by removing the oxygen element from the fire.

Complete Step by step solution:
Firstly let us know what sodium hydrogen carbonate is. Sodium hydrogen carbonate is base and is often called Sodium bicarbonate. The molecular formula for sodium bicarbonate or sodium hydrogen carbonate is ${\text{NaHC}}{{\text{O}}_{\text{3}}}$with the molecular mass of 84 g/mol. The common name of sodium bicarbonate is baking soda. It is soluble in water and gives rise to sodium and bicarbonate ions. Sodium carbonate being a base reacts with any acid to give neutralization reaction forming a salt NaCl and liberates carbon dioxide gas.
${\text{NaHC}}{{\text{O}}_{\text{3}}}{\text{ + HCl}} \to {\text{NaCl + C}}{{\text{O}}_{\text{2}}} \uparrow {\text{ + }}{{\text{H}}_{\text{2}}}{\text{O}}$
Sodium bicarbonate has many applications in various fields and its use in fire extinguishers is one the important applications. A fire extinguisher is a cylindrical device which consists of pressurized gas. The gas used inside an extinguisher differs with the application of the extinguishers. But most commonly sodium bicarbonate is used as a dry chemical extinguisher in fire cylinders. These cylinders are called Soda acid cylinders as they are made up of Sodium bicarbonate (NaHCO$_3$) and acid (${H_2}S{O_4}$) contained in it separately.
When the cylinder is opened and held in a tilted position at a certain degree angle, the reaction between the acid and the sodium hydrogen carbonate takes place to give out the carbon dioxide gas with a great amount of pressure. The reaction between the components of a fire extinguisher is as follows,${\text{2NaHC}}{{\text{O}}_{\text{3}}}_{\left( {\text{s}} \right)}{\text{ + }}{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{{\text{4}}\left( {\text{l}} \right)}} \to {\text{N}}{{\text{a}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}{\text{ + }}{{\text{H}}_{\text{2}}}{{\text{O}}_{\left( {\text{l}} \right)}}{\text{ + C}}{{\text{O}}_{{\text{2(g)}}}} \uparrow$
This liberated carbon dioxide gas when applied on to an electrical appliances on fire, the fire puts off without any electrical short circuits or any great damage.

So, Sodium hydrogen carbonate acts as a fire extinguisher is true and the option is (A).

Note: The important chemical property of sodium hydrogen carbonate is being a basic compound, upon reaction with acid undergoes neutralization reaction to give salt and water along with carbon dioxide gas.