What defines an alcohol in organic chemistry?

In organic chemistry, an alcohol is specifically characterized by the presence of a hydroxyl functional group (-OH) attached to a carbon atom. This functional group is what distinguishes alcohols from other types of organic compounds. The hydroxyl group contributes to the unique properties and reactivity of alcohols, such as their ability to form hydrogen bonds, which has implications for their melting and boiling points as well as their solubility in water.

While a carbon chain is a common feature in many organic compounds, including alcohols, simply being a molecule that contains a carbon chain does not define an alcohol. Similarly, carbonyl functional groups are characteristic of ketones and aldehydes, not alcohols, and saturation refers to the presence of single bonds between carbon atoms, which does not specifically define the alcohol classification. Thus, the key defining feature of an alcohol is the hydroxyl functional group.