(redirected from Absolute ethanol)
Also found in: Dictionary, Thesaurus, Medical.


(ĕth`ənōl') or

ethyl alcohol,

CH3CH2OH, a colorless liquid with characteristic odor and taste; commonly called grain alcohol or simply alcoholalcohol,
any of a class of organic compounds with the general formula R-OH, where R represents an alkyl group made up of carbon and hydrogen in various proportions and -OH represents one or more hydroxyl groups.
..... Click the link for more information.


Ethanol is a monohydric primary alcohol. It melts at −117.3°C; and boils at 78.5°C;. It is miscible (i.e., mixes without separation) with water in all proportions and is separated from water only with difficulty; ethanol that is completely free of water is called absolute ethanol. Ethanol forms a constant-boiling mixture, or azeotrope, with water that contains 95% ethanol and 5% water and that boils at 78.15°C;; since the boiling point of this binary azeotrope is below that of pure ethanol, absolute ethanol cannot be obtained by simple distillation. However, if benzene is added to 95% ethanol, a ternary azeotrope of benzene, ethanol, and water, with boiling point 64.9°C;, can form; since the proportion of water to ethanol in this azeotrope is greater than that in 95% ethanol, the water can be removed from 95% ethanol by adding benzene and distilling off this azeotrope. Because small amounts of benzene may remain, absolute ethanol prepared by this process is poisonous.

Ethanol burns in air with a blue flame, forming carbon dioxide and water. It reacts with active metals to form the metal ethoxide and hydrogen, e.g., with sodium it forms sodium ethoxide. It reacts with certain acids to form esters, e.g., with acetic acid it forms ethyl acetate. It can be oxidized to form acetic acid and acetaldehyde. It can be dehydrated to form diethyl ether or, at higher temperatures, ethylene.


Ethanol is the alcohol of beer, wines, and liquors. It can be prepared by the fermentation of sugar (e.g., from molasses), which requires an enzyme catalyst that is present in yeast; or it can be prepared by the fermentation of starch (e.g., from corn, rice, rye, or potatoes), which requires, in addition to the yeast enzyme, an enzyme present in an extract of malt. The concentration of ethanol obtained by fermentation is limited to about 10% (20 proof) since at higher concentrations ethanol inhibits the catalytic effect of the yeast enzyme. (The proof concentration of an alcoholic beverage is numerically double the percentage concentration.) For nonbeverage uses ethanol is more commonly prepared by passing ethylene gas at high pressure into concentrated sulfuric or phosphoric acid to form the corresponding ester; the acid-ester mixture is diluted with water and heated, forming ethanol by hydrolysis, and the alcohol is then removed from the mixture by distillation, usually with steam.


Ethanol is used extensively as a solvent in the manufacture of varnishes and perfumes; as a preservative for biological specimens; in the preparation of essences and flavorings; in many medicines and drugs; as a disinfectant and in tinctures (e.g., tincture of iodine); and as a fuel and gasoline additive (see gasoholgasohol,
a gasoline extender made from a mixture of gasoline (90%) and ethanol (10%; often obtained by fermenting agricultural crops or crop wastes) or gasoline (97%) and methanol, or wood alcohol (3%).
..... Click the link for more information.
). Many U.S. automobiles manufactured since 1998 have been equipped to enable them to run on either gasoline or E85, a mixture of 85% ethanol and 15% gasoline. E85, however, is not yet widely available. Denatured, or industrial, alcohol is ethanol to which poisonous or nauseating substances have been added to prevent its use as a beverage; a beverage tax is not charged on such alcohol, so its cost is quite low. Medically, ethanol is a soporific, i.e., sleep-producing; although it is less toxic than the other alcohols, death usually occurs if the concentration of ethanol in the bloodstream exceeds about 5%. Behavioral changes, impairment of vision, or unconsciousness occur at lower concentrations. See alcoholismalcoholism,
disease characterized by impaired control over the consumption of alcoholic beverages. Alcoholism is a serious problem worldwide; in the United States the wide availability of alcoholic beverages makes alcohol the most accessible drug, and alcoholism is the most
..... Click the link for more information.


(organic chemistry)
C2H5OH A colorless liquid, miscible with water, boiling point 78.32°C; used as a reagent and solvent. Also known as ethyl alcohol; grain alcohol.
References in periodicals archive ?
The crude material was recrystallized twice from absolute ethanol to obtain 0.70 g pure product 5c, yield 90.1 %.
After incubation, 325 [micro]l of binding buffer and 325 [micro]l of absolute ethanol were admixed into a new combined high pure filter collection tube and centrifuged for 2 min at 8000 rpm.
A mixture of the appropriate compound 2d-f (1.3 mmol) with 1 equivalent of 4-(trifluoromethyl)phenyl isothiocyanate in absolute ethanol was stirred at room temperature for 2-7 h.
TPC of CE ranged from 48.04 mg GAE/g crude (absolute ethanol extract) to 49.87 mg GAE/g crude (water extract).
We did not compare PPI treatment with a control group treated with ethanol because we could not obtain absolute ethanol. Secondly, the patients were followed up only for one year.
There was significant (p = 0.05) mean difference in the absolute ethanol volume for genotypes EUSS10, SS04, and EUSS11.
The mixture of 50% (v/v) water with methanol, ethanol, and acetone had the highest extraction yields of TPC, followed by absolute methanol and absolute ethanol, which accounted for approximately 66% and 43% of the TPC extracted by 50% acetone.
Approximately, 50 [micro]L of each partition (1.0mg/mL) was loaded and followed by 50 [micro]L of DPPH (1mM in ethanolic solution) and 150 [micro]L of absolute ethanol was added in 96-well microtiter plate in triplicate.
Absolute ethanol was bought from RCI Labscan Limited (Bangkok, Thailand).
Four solvents (absolute ethanol, absolute methanol, 80% aqueous ethanol and 80% aqueous methanol) and three techniques (orbital shaker, sonication and magnetic stirrer) were applied for this purpose.
Absolute ethanol (Prolabo) was diluted to a concentration of 6% (v/v) with tap water.
The nicotinic acid hydrazide (10 mmol, 1.37 g) was dissolved in 20 mL of absolute ethanol by heating gently on water bath.

Full browser ?