Ethanol is a volatile, flammable, colorless liquid with a pungent taste that is used as a beverage constituent.

Ethanol is a two-carbon alcohol with the molecular formula C₂H₆O and the structural formula CH₃CH₂OH. Its hydroxyl group makes the molecule polar and allows it to form hydrogen bonds, while its ethyl group contributes nonpolar character. This combination gives ethanol both hydrophilic and hydrophobic properties and makes it completely miscible with water. Ethanol undergoes characteristic alcohol reactions, including oxidation to acetaldehyde and then acetic acid, dehydration to form ethene, and reactions that produce esters or ethers. It is a weak acid and a weak base, and its intermolecular hydrogen bonding gives it a substantially higher boiling point than hydrocarbons of similar molecular mass.