Ethanol and ethyl alcohol are two names for the exact same chemical substance. This colorless, volatile liquid is the intoxicating ingredient found in all alcoholic beverages, but it also serves a wide variety of industrial and medical purposes. The difference in terminology arises from the context in which it is being discussed, such as a regulatory setting or a scientific paper.
Defining the Molecule
The compound is an organic molecule with the chemical formula $\text{C}_2\text{H}_5\text{OH}$, which can also be written as $\text{C}_2\text{H}_6\text{O}$. This formula indicates the molecule contains two carbon atoms, six hydrogen atoms, and one oxygen atom. Its classification as an alcohol stems from the presence of a hydroxyl group, which is a functional group denoted by the symbol -OH. The hydroxyl group is attached to a two-carbon chain known as an ethyl group. The oxygen atom in the hydroxyl group creates polarity in the molecule. This polarity allows the substance to readily form hydrogen bonds, making it highly miscible in water and an effective solvent for many other compounds.
Understanding the Nomenclature
The usage of “ethanol” versus “ethyl alcohol” primarily reflects the preferred naming convention within different communities. “Ethanol” is the systematic name established by the International Union of Pure and Applied Chemistry (IUPAC), which provides a standardized naming system for all chemical compounds. The IUPAC name is derived by combining the prefix “eth-” for the two-carbon chain, the infix “-an-” for the single bonds, and the suffix “-ol” to indicate the presence of an alcohol functional group.
“Ethyl alcohol” is considered the common, historical, or trade name for the compound. This name is descriptive, combining the name of the carbon chain component, the ethyl group, with the general class of compounds, alcohol. While the terms are chemically interchangeable, the name “ethanol” is generally favored in scientific and industrial literature. The common name “ethyl alcohol” is often encountered in consumer-facing contexts, especially when referring to the substance in beverages or as “grain alcohol.”
Primary Uses and Applications
The molecule’s structure allows it to serve multiple distinct roles across various industries. One of its oldest and most recognized applications is in human consumption, as it is the active ingredient in beer, wine, and spirits, produced through the fermentation of sugars by yeast. Beyond beverages, the compound is widely used as a solvent because it can dissolve both water-soluble and oil-soluble substances. This solvent property makes it a common ingredient in personal care products, such as perfumes and mouthwash, and in industrial products like lacquers and varnishes.
A major application is as a fuel source, where it is often referred to as bioethanol when produced from biomass. More than 98 percent of gasoline sold in the United States contains ethanol, typically in a blend known as E10, which is 10 percent ethanol. The addition of ethanol helps to oxygenate the fuel, which reduces air pollution and increases the octane number. Furthermore, its effectiveness in killing bacteria, fungi, and viruses makes it a common antiseptic agent used in disinfectants and hand sanitizers.