Nordhausen acid

Nordhftuser Schwefelsaure, Nordhftuser Vitri-oloL Nordhausen acid (fuming sulfuric acid), nordisch, a. northern, northerly, Nordic, nordlich, a. northerly, northern, arctic. Nord-licht, n. aurora borealis, -meer, n. Arctic Ocean, -ost, m. northeast northeaster, -pol, m. north pole. -see,/. North Sea. Norgeraniumsaure,/. norgeranic acid. Norgesalpeter, m. Norway saltpeter (calcium nitrate). 

SYNS ACIDE SULFURIQUE (FRENCH) ACIDO SOLFORICO (ITALIAN) BOV DIPPING ACID HYDROOT MATTING ACID pOT) NORDHAUSEN ACID pOT) OIL of VITRIOL pOT) SCHWEFEL-SAEURELOESUNGEN (GERMAN) SPENT SULFURIC ACID pOT) SULPHURIC ACID VITRIOL BROWN OIL VITRIOL, OIL OF pOp ZWAVELZUURO-PLOSSINGEN pUTCH)... 

Anhydrous or dry sulphuric acid is obtamed by heating Nordhausen acid (566 So, 3858) in a glass retort connected with a well-cooled receiver. 

Properties.—The commercial Nordhausen acid, which is a mixture of HjSaO, with excess of SOa, or of H,SO , is a brown, oily liquid, which boils below 100° (212° F.) giving off SOs and is solid or liquid according to the temperature. It is used chiefly as a. solvent for indigo, and in the anilin industry. 

Synonyms cas 7664-93-9 vitriol brown oil oil of vitriol hydroot dipping acid nordhausen acid ... 

Nonylphenoxy)-3,6,9,12,15-pentaoxaheptadecan-1-ol, dihydrogen phosphate. See Nonoxynol-6 phosphate 14-(Nonylphenoxy)-3,6,9,12-tetraoxatetradecan-1-ol. See Nonoxynol-5 Nonylphenyl phosphite (3 1). SeeTris (nonylphenyl) phosphite Nonyl phenyl polyethylene glycol Nonyl phenyl polyethylene glycol ether. SeeNonoxynol Nordhausen acid. See Sulfuric acid Normal hexane. See Hexane Normal lead acetate. See Lead acetate Normal propyl alcohol. See Propyl alcohol... 

Nordhausen acid. See Sulfuric acid Nordihydroguaiaretic acid CAS 500-38-9 EINECS/ELINCS 207-903-0 Synonyms 1,4-Bis (3,4-dihydroxyphenyl)-2,3-di methyl butane Dihydronorguaiaretic acid P,y-Dimethyl-a,A-bis (3,4-dihydroxyphenyl) butane 4,4 -(2,3-Dimethyl-1,4-butanediyl) bis [1,2-benzenediol] 4,4 -(2,3-Dimethyltetramethylene) dipyrocatechol NDGA Nordihydroguairaretic acid Classification Organic compd. 

Matting acid Nordhausen acid Oil of vitriol Sulphuric acid Vitriol brown oil Vitriol, oil of... 

Fe2(S04)3 + 2FcS04 + heat -> 4SO3 + SO2 + 2Fc203 SO3 (sulfur trioxide) + H2SO4 H2S2O7 (Nordhausen acid)... 

During the Middle Ages, pyrites were called vitriol. The alchemical lingo for ferrous sulfate was called green vitriol, while cupric sulfate was called blue vitriol. Sulfuric acid, itself, being produced from these products, was first known as oil of vitriol. Another name for such fuming acid was Nordhausen acid. This material is a special case of sulfuric acid, where almost no water is present. Whereas normal sulfuric acid is sulfur trioxide dissolved in water, fuming acid is sulfur trioxide dissolved in concentrated sulfuric acid. 

The major limitation of the Chamber process was the strength of the acid it produced, even after distillation. Acid from the Chamber process could be concentrated, using platinum stills, but only up to 78%. A special feature of the new Contact process was the ability to make fuming acid still basically the monopoly of the very expensive and limited Nordhausen acid. 

The demand for such stronger acid had been small, until the emergence of the dyestuffs industry in the 1870 s. Then, Rudolf Messel (1848 - 1920) in London, and Clemens Alexander Winkler (1838 - 1904) in Freiberg, worked on the process. A key part of their invention was the use of powdered platinum as the catalyst. The German-bom Messel had been a chemist in the firm Squire, Chapman, and Company from 1875 to 1878. The improved, yet still flawed, technology was first installed at their sulfuric acid plant at Silvertown in 1876. In 1878, Messel became a partner in the renamed firm Spencer, Chapman and Messel, where he was Managing Director until 1916. In 1875, developments by Winkler had led to another Contact plant to be opened in Frieberg. While the new plants were competitive versus the expensive Nordhausen acid, the process was still costly and difficult to operate. Impurities in the system, especially arsenic, poisoned the catalyst. Except for a few special cases, the Contact process was still only a technical curiosity. 

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