Question

Define an acid.

Answer 1

An acid is a compound that can produce hydrogen ions (H⁺) in its aqueous solution. A H⁺ ion cannot exist independently; therefore, it combines with one water molecule to form a hydronium ion (H₃O⁺). Thus, an acid is a compound that produces a hydronium ion (H₃O⁺) as positive ion when dissolved in water.
Example:
CH₃COOH + H₂O ⇌ H₃O⁺ + CH₃COO^-
Acetic acid Acetate ion