Which functional group is indicated by the suffix "-one" in IUPAC nomenclature?

In IUPAC nomenclature, the suffix "-one" specifically indicates the presence of a ketone functional group. Ketones are characterized by having a carbonyl group (C=O) attached to two carbon atoms. This suffix is used to denote the simplest case, where the carbonyl group appears within the carbon chain, as opposed to being at the end of the chain.

When naming a ketone, the longest carbon chain that contains the carbonyl group is identified and the "-one" suffix is added to the name of the alkane corresponding to that chain length. For example, if you have a ketone derived from a six-carbon alkane (hexane), the name would be hexanone, indicating it contains a carbonyl group with the appropriate positioning based on the molecule's structure.

The other functional groups noted, such as alcohols, aldehydes, and ethers, utilize different suffixes or prefixes that distinguish them from ketones. Alcohols are designated with the suffix "-ol," aldehydes with "-al," and ethers often use the prefix "alkoxy." The unique identification of functional groups through nomenclature helps in understanding the structure and reactivity of organic compounds.