What Happens to an Acid or a Base in a Water Solution

Acid is a chemical substance that releases hydrogen ions (H⁺) when dissolved in water. Acids often have a sour taste and can turn blue litmus paper red. Some common examples of acids are Hydrochloric acid (HCl), Carbonic acid (H₂CO₃), Citric acid, etc.

Base, on the other hand, is a chemical substance that, when dissolved in water, releases hydroxide ions (OH^–). Bases often have a bitter taste and can turn red litmus paper blue. Common examples of bases include sodium hydroxide (NaOH), potassium hydroxide (KOH), and ammonia (NH₃), etc.

When an acid or a base is dissolved in water, it undergoes a process called dissociation, leading to the formation of ions. The following changes occur when an acid or a base is dissolved in the water.

Acid in a Water Solution

When an acid is dissolved in water, dissociation occurs, forming the conjugate base. This process is done in the following steps:

Step 1: Proton Donation: Acids are substances that can donate protons (H⁺ ions). When an acid is dissolved in water, it donates a proton to a water molecule.

Step 2: Formation of Hydronium Ions (H₃O⁺): The proton donated by the acid combines with a water molecule to form a hydronium ion (H₃O⁺), leaving behind a conjugate base.

Example:

HCl + H₂O ⟶ H₃O⁺+ Cl⁻

Base in a Water Solution

When a base is dissolved in water, dissociation occurs. This process is done in the following steps:

Step 1: Hydroxide Ion Formation: Bases are substances that can accept protons (H⁺ ions) or donate hydroxide ions (OH⁻). When a base is dissolved in water, it accepts a proton from a water molecule or donates a hydroxide ion.

Step 2: Formation of Hydroxide Ions (OH⁻): In the case of strong bases, such as sodium hydroxide, the base completely dissociates into ions, leading to the presence of hydroxide ions in the solution.

Example:

NaOH (aq) → Na⁺(aq) + OH⁻(aq)