The hydrogen centre in the carboxyl group (−COOH) in carboxylic acids such as acetic acid can separate from the molecule by ionization:
CH₃COOH ⇌ CH₃CO₂⁻ + H⁺
Because of this release of the proton (H⁺), acetic acid has acidic character.
Acetic acid is a weak monoprotic acid.
In aqueous solution, it has a pKₐ value of 4.76.
Its conjugate base is acetate (CH₃COO⁻).
A 1.0 M solution (about the concentration of domestic vinegar) has a pH of 2.4, indicating that merely 0.4% of the acetic acid molecules are dissociated.
However, in very dilute (< 10⁻⁶ M) solution acetic acid is >90% dissociated.
The hydrogen centre in the carboxyl group (−COOH) in carboxylic acids such as acetic acid can separate from the molecule by ionization:
CH₃COOH ⇌ CH₃CO₂⁻ + H⁺
Because of this release of the proton (H⁺), acetic acid has acidic character. Acetic acid is a weak monoprotic acid. In aqueous solution, it has a pKₐ value of 4.76. Its conjugate base is acetate (CH₃COO⁻). A 1.0 M solution (about the concentration of domestic vinegar) has a pH of 2.4, indicating that merely 0.4% of the acetic acid molecules are dissociated. However, in very dilute (< 10⁻⁶ M) solution acetic acid is >90% dissociated.
Acetic acid