A sample of solid ammonium chloride, NH4Cl, is dissolved in water. The solution formed was found to be acidic. Can you please explain why the solution is acidic?

The ammonium ion (NH4^+) is hydrolyzed according to this equation.

NH4^+ + H2O ==> H3O^+ + NH3
(H3O^+) = acidic

Certainly! The solution of solid ammonium chloride in water is acidic because it undergoes hydrolysis. Hydrolysis is a chemical reaction in which a compound reacts with water to produce an acidic or basic solution.

Ammonium chloride (NH4Cl) dissociates in water to form ammonium ions (NH4+) and chloride ions (Cl-). The ammonium ion (NH4+) acts as a weak acid in water, undergoing a hydrolysis reaction:

NH4+ (aq) + H2O (l) ⇌ NH3 (aq) + H3O+ (aq)

In this reaction, the ammonium ion (NH4+) reacts with water (H2O) to produce ammonia (NH3) and hydronium ion (H3O+), which is the characteristic of an acidic solution. The hydronium ion (H3O+) is responsible for the acidity of the solution.

Therefore, when solid ammonium chloride is dissolved in water, the resulting solution is acidic due to the hydrolysis of the ammonium ion.