In chemistry, hydroxide's the name for the diatomic anion OH−, consisting of oxygen and hydrogen atoms, usually derived from the dissociation of a base. It's one of the simplest diatomic ions known. Inorganic compounds that contain the hydroxyl group are referred to as hydroxides. Common hydroxides include: Sodium hydroxide, NaOH Potassium hydroxide, KOH Calcium hydroxide, Ca(OH)2 Hydroxide as a base Most compounds containing hydroxide are bases. An Arrhenius base's a substance that pr… (More on Hydroxide)