An organic compound is considered an alcohol if it has what functional group?

The story behind the answer

Alcohols are defined by the presence of a hydroxyl group (–OH) bonded to a saturated (sp3) carbon atom. This –OH group enables hydrogen bonding, which raises boiling points and increases solubility in water compared to similar-sized hydrocarbons. By contrast, a carbonyl (C=O) group characterizes aldehydes and ketones, the aldehyde group is –CHO specifically, and an alkyl group is just a hydrocarbon substituent, not a functional group that defines a class of compounds.

A quick memory aid: “OH? That’s alcohol!” Many alcohols are named with the suffix –ol (methanol, ethanol). Note that when –OH attaches to an aromatic ring, the compound is called a phenol, which has distinct properties from regular alcohols.