Sodium Bicarbonate

Sodium bicarbonate (NaHCO₃), also known as baking soda or sodium hydrogen carbonate, is a white powder that readily dissolves in water to produce sodium (Na⁺) ions and bicarbonate (HCO₃) ions. In the presence of acids, these ions create carbon dioxide gas (CO₂) and water. Baking soda, a weak base, is used in antacids, fire extinguishers, and baking powder. In almost all of its common uses, sodium bicarbonate is employed to produce carbon dioxide gas.

When sodium bicarbonate is heated above 518°F (270°C) it decomposes and produces carbon dioxide. Since carbon dioxide gas is more dense than air, it tends to sink; thus carbon dioxide can smother a fire by obstructing the flow of oxygen to the fuel, which needs oxygen to continue burning. Sodium bicarbonate is employed in fire extinguishers and is widely used on electrical fires.