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
Hexafluorosilicic acid HF. It reacts faster with "t"-butyldimethysilyl (TBDMS) ethers than triisopropylsilyl (TIPS) ethers. Hexafluorosilicic acid and the salts are used as wood preservation agents. Hexafluorosilicic acid can release hydrogen fluoride when evaporated, so it has similar risks. Inhalation of the vapors may cause lung edema. Like hydrogen fluoride, it attacks glass and stoneware. The LD value of hexafluorosilicic acid is 430 mg/kg. Hexafluorosilicic acid Hexafluorosilicic acid is an inorganic compound with the chemical formula (also written as ). It is a colorless liquid rarely encountered undiluted. Hexafluorosilicic acid has a distinctive sour taste and pungent smell. It is produced naturally on