Alcohols are a class of organic molecules possessing at least one hydroxyl functional group connected to a carbon atom. Methanol and ethanol are two familiar alcohols. Both are aliphatic alcohols, meaning that they are derived from a hydrocarbon and do not contain a benzene group.
There are three classifications of aliphatic alcohols. The first is a primary alcohol, where the hydroxyl group is connected to a carbon atom that is connected to one carbon-based, or alkyl, group. In a secondary alcohol, the hydroxyl group is connected to a carbon atom that has two alkyl groups. Finally, in a tertiary alcohol, the hydroxyl group is connected to a carbon atom with three alkyl groups.
Alcohols can also be aromatic, in which a hydroxyl group is connected directly to the carbon of a benzene ring. The simplest form of an aromatic alcohol is phenol. Compounds that contain phenol are known as phenol derivatives or phenols.
Certain reactions undergone by alcohols can be used to distinguish them based on visible differences in the reaction’s outcome. One such reaction is the ferric chloride test, which tests for the presence of phenols. When ferric chloride is added to a phenol, a purple iron-thr
