In the above reaction, the proton H+ from CH3COOH (acetic acid) is donated to water, producing H3O+ and a CH3COO-. The bonds between H+ and CH3COO- are broken by the addition of water molecules. A reaction with CH3COOH, a weak acid, is similar to an acid-dissociation reaction, and water forms a conjugate base and a hydronium ion. When a weak acid is hydrolyzed, a hydronium ion is produced