Ammonia (NH3) and hydrochloric acid (HCl) react to form ammonium chloride (NH4Cl). This reaction is an example of an acid-base reaction, also known as neutralization. In this type of reaction, an acid and a base react to form a salt and water.

The chemical equation for the reaction between ammonia and hydrochloric acid is:

NH3 + HCl → NH4Cl

In this reaction, ammonia acts as the base, while hydrochloric acid acts as the acid. The products of the reaction are ammonium chloride, a salt, and water.

Acid-base reactions are characterized by the transfer of protons (H+) from the acid to the base. In the case of ammonia and hydrochloric acid, the proton from the hydrochloric acid is transferred to the ammonia, resulting in the formation of ammonium chloride and water.