What does the suffix "-ol" signify in organic chemistry?

The suffix "-ol" in organic chemistry is a systematic way of indicating that a molecule belongs to the alcohol functional group. Alcohols are characterized by the presence of one or more hydroxyl (-OH) groups attached to a carbon atom. This feature of the molecule is critical in distinguishing alcohols from other types of compounds.

When a compound is named with the suffix "-ol," it signifies that the hydroxyl group is a key functional group, which significantly influences the chemical properties of the molecule. For example, alcohols typically exhibit different solubility, boiling points, and reactivity compared to hydrocarbons or other functional groups.

The other options do not utilize the suffix "-ol" to designate their respective functional groups, making them irrelevant in this context. Ethers, for instance, contain an oxygen atom bonded to two carbon atoms but are named with the suffix "-ether." Aromatic compounds refer to a specific structure involving cyclic arrangements of carbon with delocalized pi electrons and do not include the "-ol" suffix. Alkanes are saturated hydrocarbons and are generally named with the "-ane" suffix, indicating the absence of functional groups like alcohols. Thus, the correct answer is that the suffix "-ol" signifies an alcohol.