Question

What is a soda fire extinguisher?

Answer 1

Soda fire extinguisher

• Sodium bicarbonate $\left({\mathrm{NaHCO}}_3\right)$ and sulphuric acid $\left({\mathrm{H}}_2{\mathrm{SO}}_4\right)$ are used in soda-acid fire extinguishers.
• It is the most effective fire extinguisher for home usage.

Working

• The fire extinguisher contains sodium bicarbonate $\left({\mathrm{NaHCO}}_3\right)$ in water solution as well as sulfuric acid $\left({\mathrm{H}}_2{\mathrm{SO}}_4\right)$ in a separate bottle.
• By turning the knob on the fire extinguisher, the sulphuric acid reacts with the sodium bicarbonate solution and produces a little amount of carbon dioxide gas $\left({\mathrm{CO}}_2\right)$.
• Carbon dioxide is a non-combustible gas that does not support combustion.
• It is heavier than air and hence cuts off the oxygen supply to the air, putting out the flames.
• The reaction can be shown as:

$2{\mathrm{NaHCO}}_3\left(\mathrm{aq}\right)+{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)\stackrel{}{\to }{\mathrm{Na}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+2{\mathrm{CO}}_2\left(\mathrm{g}\right)$