Final answer:
When gaseous ammonia reacts with gaseous hydrochloric acid, the resultant solid compound is ammonium chloride (NH4Cl) and it is soluble in water.
Step-by-step explanation:
When gaseous ammonia reacts with gaseous hydrochloric acid, the resulting compound is ammonium chloride (NH4Cl). Ammonium chloride is a solid compound and it is soluble in water.
Ammonium chloride is formed when the strong acid HCl is neutralized by the weak base NH3. In water, ammonium chloride dissociates into ammonium ions (NH4+) and chloride ions (Cl-). The chloride ion is incapable of hydrolyzing because it is the conjugate base of the strong acid HCl. However, the ammonium ion can react slightly with water, donating a proton and acting as an acid.
Therefore, the resultant solid compound is ammonium chloride (NH4Cl) and it is soluble in water.