Alcohols may be called as hydroxy derivatives of aliphatic hydrocarbons. Alcohols resemble water in their acidity and basicity and in their ability to form hydrogen bond
Alcohols can be represented by the general formula ROH, where R is any alkyl or substituted alkyl group. The group may be primary, secondary, or tertiary; it may be open-chain or cyclic; it may contain a double bond, a halogen atom, or an aromatic ring.
For example :
All alcohol contains the hydroxyl (-OH) group, which, as the functional group, determines the properties characteristic of this family. Variations in structure of the R group may affect the rate at which the alcohol undergoes certain reactions, and even, in a few cases, may affect the kind of reaction.
When the hydroxyl group is attached directly to an aromatic ring they are phenols, and differ so markedly from the alcohols that we shall consider them separately.