Ethanol
Definition and meaning of Ethanol in chemistry.
Ethanol is a clear, volatile, and flammable liquid with a characteristic odor, serving as the principal psychoactive compound in human alcoholic beverages. It is a simple aliphatic alcohol consisting of an ethyl group covalently bonded to a single hydroxyl group.
In more detail
At the molecular level, ethanol exhibits strong intermolecular hydrogen bonding due to its polar hydroxyl group, which gives it a substantially higher boiling point than similar-sized alkanes and makes it fully miscible with water in all proportions. It is produced biologically by the anaerobic fermentation of sugars by specific yeasts, a biochemical pathway used extensively worldwide in commercial brewing and winemaking. Industrially, pure ethanol is synthesized through the acid-catalyzed hydration of ethylene, primarily intended for use as a versatile laboratory solvent, a synthetic chemical intermediate, or a combustible fuel additive. In automotive fuels, it is frequently blended with standard gasoline to oxygenate the mixture, promoting more complete engine combustion and significantly reducing tailpipe emissions of toxic carbon monoxide. Inside the human body, consumed ethanol is rapidly metabolized in the liver by the enzyme alcohol dehydrogenase into acetaldehyde, a highly reactive and toxic intermediate that is subsequently converted to harmless acetate.
Key facts
| Field | Organic Chemistry |
|---|---|
| Formula | C2H5OH |
| Molar mass | 46.07 g/mol |
| Boiling point | 78.37 °C |
| Density | 0.789 g/cm³ |
E85 is a widely distributed alternative transportation fuel mixture containing 85% ethanol and 15% gasoline, designed specifically for use in modified flexible-fuel internal combustion vehicles.
Frequently asked questions
Why is ethanol used as an antiseptic in hand sanitizers?
Ethanol physically disrupts the protective lipid bilayer of cell membranes and rapidly denatures critical internal proteins, effectively killing many bacteria, fungi, and lipid-enveloped viruses, especially at optimal concentrations of 60% to 80% in water.
What makes ethanol completely soluble in liquid water?
The polar hydroxyl group in ethanol can easily form hydrogen bonds with surrounding water molecules. Since the nonpolar ethyl hydrocarbon chain is relatively short, the polar interactions dominate, allowing ethanol to seamlessly mix with water.