When hydrochloric acid (HCl) is mixed with sodium hydrogen carbonate (NaHCO₃), the mixture produces a noticeable fizzing reaction. This reaction occurs because carbon dioxide gas (CO₂) is released as a product of the reaction.
The chemical equation for this reaction is:
NaHCO₃ + HCl → NaCl + H₂O + CO₂
In this equation, sodium chloride (NaCl) and water (H₂O) are also formed alongside carbon dioxide. The fizzing you see is the carbon dioxide gas escaping from the solution, creating bubbles that rise to the surface.
This reaction is a classic example of an acid-base reaction where the sodium hydrogen carbonate, a weak base, neutralizes the hydrochloric acid, a strong acid.