Final answer:
Acetic acid (CH₃COOH) is a weak acid because it only partially dissociates in water, with about 99.6% of the acetic acid molecules remaining undissociated in a 1 M aqueous solution.
Step-by-step explanation:
Type of Acid: CH₃COOH
Acetic acid, with the chemical formula CH₃COOH, is classified as a weak acid. Unlike strong acids, which dissociate completely in water, acetic acid only partially dissociates in aqueous solution. In the case of 1 M acetic acid, only about 0.4% of the acetic acid molecules dissociate into H⁺ (aq) and CH₃COO⁻ (aq) ions. The reversible nature of this dissociation indicates its status as a weak acid. The vast majority of the acid remains as undissociated molecules in solution, which is characteristic of weak acids.
Strong acids are defined by their ability to dissociate 100% into ions in water. Since acetic acid does not meet this criterion, it cannot be classified as a strong acid. This fundamental property of acetic acid determines its behavior in chemical reactions, including its role in creating a weak acidic solution when dissolved in water. The chemical equation representing the dissociation of acetic acid is written as a reversible reaction:
CH₃COOH(aq) ↔ H⁺(aq) + CH₃COO⁻(aq)