Definition of an Alcohol
An alcohol is an organic compound characterized by the presence of a hydroxyl (-OH) functional group attached to a saturated carbon atom. This carbon atom must be part of an alkyl or substituted alkyl group. The general formula for a simple open-chain alcohol is R-OH, where 'R' represents an alkyl group (a chain of carbon and hydrogen atoms).
Key Properties
The hydroxyl group makes alcohols polar, enabling them to form hydrogen bonds with each other and with water molecules. This strong intermolecular attraction results in higher boiling points compared to hydrocarbons of similar molecular weight. Smaller alcohols, like methanol and ethanol, are readily soluble in water due to their ability to hydrogen bond.
Common Examples and Structures
A widely known example is ethanol (CH₃CH₂OH), which is the alcohol found in alcoholic beverages. Another common one is methanol (CH₃OH), often used as a solvent and fuel, but highly toxic. Isopropanol (rubbing alcohol, (CH₃)₂CHOH) is another familiar alcohol used as an antiseptic.
Importance and Applications
Alcohols are incredibly versatile and have numerous applications across industries. They serve as excellent solvents for various substances, are used as fuels (e.g., bioethanol), and are crucial raw materials in the synthesis of other organic compounds. Medically, they are effective disinfectants and antiseptics.