Question

What does a soda-acid type fire extinguisher contain? How does it work? Explain the working of a soda-acid fire extinguisher with the help of a labelled diagram.

Answer 1

A soda-acid type of fire extinguisher contains solutions of sulphuric acid and sodium hydrogencarbonate in separate containers.
The working of a soda-acid fire extinguisher is described below:

  

When the knob of the fire extinguisher is pressed, the sulphuric acid mixes with the sodium hydrogencarbonate solution to produce a substantial quantity of carbon dioxide gas. The carbon dioxide gas forces out as a stream of liquid that falls on the burning substance because of the high pressure within the extinguisher. A blanket of carbon dioxide comes out along with the liquid formed around the burning substance and cuts off the supply of air to the burning substance. When the supply of air is cut off, and the fire gets extinguished.
The reaction involved is given below.

2NaHCO₃ + H₂SO₄ → Na₂SO₄ + 2H₂O + 2CO₂