When hydrochloric acid (HCl) is added to sodium hydrogen carbonate (NaHCO3), a chemical reaction takes place, resulting in the formation of several products. Here's what happens:

1. Initial Reaction:

When HCl, a strong acid, comes into contact with NaHCO3, a base, a neutralization reaction occurs. The hydrogen ions (H+) from HCl react with the bicarbonate ions (HCO3-) from NaHCO3 to form carbonic acid (H2CO3).

HCl + NaHCO3 → H2CO3 + NaCl

2. Decomposition of Carbonic Acid:

Carbonic acid is unstable and immediately decomposes into water (H2O) and carbon dioxide (CO2) gas. This decomposition is evident by the formation of bubbles and fizzing.

H2CO3 → H2O + CO2↑

3. Formation of Sodium Chloride:

The remaining sodium ions (Na+) from NaHCO3 combine with chloride ions (Cl-) from HCl to form sodium chloride (NaCl), which is a neutral salt.

Na+ + Cl- → NaCl

4. Final Products:

The overall reaction between hydrochloric acid and sodium hydrogen carbonate results in the formation of water, carbon dioxide gas, and sodium chloride.

Overall: HCl + NaHCO3 → H2O + CO2↑ + NaCl

The reaction between hydrochloric acid and sodium hydrogen carbonate is a classic example of an acid-base reaction, where an acid and a base react to form water, salt, and sometimes gas, depending on the reactants involved.