In chemistry, an alcohol is any organic compound in which a hydroxyl group (-OH) is bound to a carbon atom of an alkyl or substituted alkyl group. The general formula for a simple acyclic alcohol is CnH2n+1OH. In common terms, the word alcohol refers to ethanol, the type of alcohol found in alcoholic beverages.
Ethanol is a colorless, volatile liquid with a mild odor which can be obtained by the fermentation of sugars. (Industrially, it is more commonly obtained by ethylene hydration—the reaction of ethylene with water in the presence of phosphoric acid.) Ethanol is the most widely used depressant in the world, and has been for thousands of years. This sense underlies the term alcoholism (addiction to alcohol).
Other alcohols are usually described with a clarifying adjective, as in isopropyl alcohol (propan-2-ol) or wood alcohol (methyl alcohol, or methanol). The suffix -ol appears in the “official” IUPAC chemical name of all alcohols.
There are three major subsets of alcohols: primary (1°), secondary (2°) and tertiary (3°), based upon the number of carbon atoms the C-OH group’s carbon (shown in red) is bonded to. Ethanol is a simple ‘primary’ alcohol. The simplest secondary alcohol is isopropyl alcohol (propan-2-ol), and a simple tertiary alcohol is tert-butyl alcohol.
When a person drinks alcohol, the alcohol is absorbed by the stomach, enters the bloodstream, and goes to all the tissues. The effects of alcohol are dependent on a variety of factors, including a person’s size, weight, age, and sex, as well as the amount of food and alcohol consumed. The disinhibiting effect of alcohol is one of the main reasons it is used in so many social situations. Other effects of moderate alcohol intake include dizziness and talkativeness; the immediate effects of a larger amount of alcohol include slurred speech, disturbed sleep, nausea, and vomiting. Alcohol, even at low doses, significantly impairs the judgment and coordination required to drive a car safely. Low to moderate doses of alcohol can also increase the incidence of a variety of aggressive acts, including domestic violence and child abuse. Hangovers are another possible effect after large amounts of alcohol are consumed; a hangover consists of headache, nausea, thirst, dizziness, and fatigue.
Prolonged, heavy use of alcohol can lead to addiction (alcoholism). Sudden cessation of long term, extensive alcohol intake is likely to produce withdrawal symptoms, including severe anxiety, tremors, hallucinations and convulsions. Long-term effects of consuming large quantities of alcohol, especially when combined with poor nutrition, can lead to permanent damage to vital organs such as the brain and liver. In addition, mothers who drink alcohol during pregnancy may give birth to infants with fetal alcohol syndrome. These infants may suffer from mental retardation and other irreversible physical abnormalities. In addition, research indicates that children of alcoholic parents are at greater risk than other children of becoming alcoholics.