An acid which is very soluble in water and gives rise to acid, neutral and alkali salts.
An acid formed by oxidation of phosphorus. The phosphoric acids are orthophosphoric acid, H3P04; pyrophosphoric acid, H4P207; metaphosphoric acid, HP03; and hypophosphoric acid, H4P206. The salts of these acids are phosphates. Orthophosphoric acid, a tribasic acid, is used as a 30% to 50% solution to etch enamel of teeth in preparation for bonding of resin dental restorations.