Diethyl Ether(redirected from Et2o)
Also found in: Dictionary, Thesaurus, Medical.
(also ether), (C2H5)2O, the most important ether.
Diethyl ether takes the form of a colorless, mobile liquid with a characteristic odor. It has a melting point of – 116.2°C, a boiling point of 34.6°C, and a density of 0.713 g/cm3 at 20°C. Miscible in all proportions with alcohol and many other organic solvents, it is only 6.6-percent soluble in water at 20°C. It readily dissolves fats. Diethyl ether forms an azeotropic mixture with water; the mixture is 98.74-percent diethyl ether, and it has a boiling point of 34.25°C. Diethyl ether is highly flammable, and it forms explosive mixtures with air in concentrations of 1.71–48.0 percent by volume. Upon storage, it is slowly oxidized by atmospheric oxygen to form explosive peroxide compounds.
Diethyl ether is produced from ethyl alcohol at a temperature of 130°–140°C by the action of sulfuric acid—hence, its trivial name in Russian, sernyi efir (sulfuric ether). It may also be produced at 200°–250°C by the vapor-phase dehydration of ethyl alcohol over aluminum oxide (Al2O3) or potassium alums. Diethyl ether is used in industry as a solvent and extracting agent—for example, in the production of powders, motion-picture film, and photographic film. It also has various laboratory uses (seeGRIGNARD REACTION).
In medicine, two grades of diethyl ether are used—medicinal and highly purified. The former is usually applied externally or used for the preparation of tinctures and extracts; it is occasionally taken internally for vomiting. The latter is inhaled as an anesthetic before surgery or sometimes taken as an enema in the form of an oil to reduce pain during childbirth.
The maximum permissible concentration of diethyl ether vapor in the air is 0.3 mg per liter.