Soda acid fire extinguishers

As the gas pressure inside the extinguisher increases, it pushes a jet of water out of the extinguisher s nozzle. Because soda acid extinguishers expel water, they should only be used on class "A" fires. Class "A" fires are those that involve wood, paper, cardboard, and cloth. Soda-acid fire extinguishers should never be used on electrical or grease fires because the water they use can cause these kinds of fires to spread and burn out of control. 

Figure 4.1 In a soda-acid fire extinguisher, a chemical reaction between an acid (sulfuric acid) and a base (baking soda) produces a jet of water that can put out certain kinds of fires.

Research how a soda-acid fire extinguisher works, and write the chemical equation for the reaction. Check your house and other structures for different types of fire extinguishers, and ask your local fire department to verify the effectiveness of each type of extinguisher. 

In a soda-acid fire extinguisher, concentrated sulfuric acid reacts with sodium hydrogen carbonate to produce carbon dioxide, sodium sulfate, and water. 

Carbon dioxide is used in the manufacture of sodium carbonate by the ammonia-soda process, urea, salicyclic acid (for aspirin), fire extinguishers and aerated water. Lesser amounts are used to transfer heat generated by an atomic reactor to water and so produce steam and electric power, whilst solid carbon dioxide is used as a refrigerant, a mixture of solid carbon dioxide and alcohol providing a good low-temperature bath (195 K) in which reactions can be carried out in the laboratory. 

Sodium carbonate (Na CO ) is the eleventh most used industrial chemical in the United States. It is commonly used as a bleaching agent and is manufactured in a two-step process. First, ammonia is combined with carbon dioxide to form sodium chloride and water, which reacts to form sodium bicarbonate and ammonium chloride (NH + CO + NaCl + H O —> NaHCOj + NH Cl). Sodium bicarbonate, commonly known as baking soda, is used as a leavening agent in baking, as an antacid to relieve stomach acid, and as a component for fire extinguishers. The second step is known as the Solvay process, wherein the sodium bicarbonate is heated and converted into sodium carbonate (NaHCO A— Na CO + H O + CO ). 

---