If less than 1% of ethanoic acid is ionized in an instant, ethanoic acid is considered a weak acid.
Ethanoic (acetic) acid ionization: CH₃COOH(aq) ⇄ CH₃COO⁻(aq) + H⁺(aq).
In water ethanoic acid is mainly in CH₃COOH form, only 1% in CH₃COOH and H⁺ ions, because it gives little hydrogen ions, this acid is considered weak monoprotic acid.
In aqueous solution, acetic acid has a pKa value of 4.76.
