The reaction between an ammonium ion (NH₄⁺) and water (H₂O) to produce a hydronium ion (H₃O⁺) when the ammonium ions act as Bronsted-Lowry acids in water can be represented by the following balanced chemical equation:
NH₄⁺ + H₂O → H₃O⁺ + NH₃
In this reaction, the ammonium ion acts as an acid by donating a proton (H⁺) to water, forming the hydronium ion (H₃O⁺) and leaving behind the ammonia molecule (NH₃) as a base.