Oleum

oleum

[′ō·lē·əm]

(chemistry)

Latin name for oil.

(inorganic chemistry)

fuming sulfuric acid

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Oleum

 

(or fuming sulfuric acid), a solution of sulfur trioxide, SO₃, in anhydrous sulfuric acid. It is a colorless liquid that fumes in moist air because of the reaction between the vapors of SO₃ and H₂O, which leads to the formation of poorly volatile H₂SO₄. Oleum containing 18–20 percent SO₃ is usually produced; the SO₃ content is sometimes as high as 60 percent. Oleum is used for sulfation of organic compounds.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.