4-Hydroxybenzoate 4-Hydroxybenzoate ion 456-23-5 Benzoic acid, 4-hydroxy-, ion(1-) Benzoic acid, p-hydroxy-, ion(1-) p-Hydroxybenzoate p-Hydroxybenzoate anion p-Hydroxybenzoic acid ion(1-) p-Hydroxybenzoic acid monoanion