Why is carbonated water acidic?

Carbonated water is acidic because carbon dioxide (CO₂) dissolves in water and forms carbonic acid (H₂CO₃).

Chemical reaction:

CO₂ + H₂O ⇌ H₂CO₃

What happens next:

Carbonic acid (H₂CO₃) is a weak acid

It partially dissociates:

H₂CO₃ ⇌ H⁺ + HCO₃⁻

The release of H⁺ ions makes the solution acidic

pH level:

Carbonated water typically has a pH of around 3 to 4

Lower than neutral water (pH 7)

Key Takeaway:

Carbonated water is acidic due to the formation of carbonic acid, which releases H⁺ ions, lowering the pH.