Terephthalic acid Terephthalic acid Terephthalic acid is an organic compound with formula CH(COH). This white solid is a commodity chemical, used principally as a precursor to the polyester PET, used to make clothing and plastic bottles. Several million tonnes are produced annually. The common name is derived from the turpentine-producing tree "Pistacia terebinthus" and phthalic acid. Terephthalic acid was first isolated (from turpentine) by the French chemist Amédée Cailliot (1805–1884) in 1846. Terephthalic acid became industrially important after World War II. Terephthalic acid was produced by oxidation of "p"-xylene with dilute nitric acid. Air oxidation of "p"-xylene gives "p"-toluic acid, which resists
Periodic acid Periodic acid Periodic acid ( "per-iodic") is the highest oxoacid of iodine, in which the iodine exists in oxidation state VII. Like all periodates it can exist in two forms: orthoperiodic acid, with the chemical formula HIO and metaperiodic acid, which has the formula HIO. Periodic acid was discovered by Heinrich Gustav Magnus and C. F. Ammermüller in 1833. Modern industrial scale production involves the electrochemical oxidation of iodic acid, on a PbO anode, with the following standard electrode potential: Orthoperiodic acid can be dehydrated to give metaperiodic acid by heating to 100 °C Further heating to around 150 °C