The reaction between ammonia and dilute hydrochloric acid results in the formation of ammonium chloride. This reaction can be represented as follows:

NH3(aq) + HCl(aq) -> NH4Cl(aq)

In this reaction, ammonia acts as a base, accepting a hydrogen ion (H+) from hydrochloric acid to form ammonium ion (NH4+). Hydrochloric acid, on the other hand, acts as an acid, donating a hydrogen ion to ammonia. The resulting product, ammonium chloride, is a salt that is soluble in water.