chemicalnomenclature

Chemical nomenclature is the systematic naming of chemical substances to provide a clear and unambiguous way to identify compounds. It covers both organic and inorganic compounds and is used in education, research, publishing, and regulatory contexts to ensure consistent communication across languages and disciplines.

In organic chemistry, the dominant framework is IUPAC nomenclature. The substitutive approach names the compound as a derivative of a parent hydrocarbon chain or ring, with substituents indicated by prefixes and locants. The root name conveys the number of carbon atoms, and suffixes reflect functional groups and bond types: -ane for single bonds, -ene for double bonds, -yne for triple bonds; -ol for alcohols, -al for aldehydes, -one for ketones, and -oic acid for carboxylic acids. Stereochemistry can be specified with descriptors such as R/S and E/Z. Examples include 3-chloropentane, hex-1-ene, and 2-methylpentan-2-ol. While many common names (ethanol, acetic acid) persist, they are not without ambiguity and are increasingly supplemented or replaced by systematic names.

In inorganic nomenclature, several conventions are used. The stock (or classical) system indicates oxidation state with Roman numerals, as in ferric chloride (FeCl3) and ferrous chloride (FeCl2). Systematic naming extends to polyatomic ions (nitrate, sulfate) and coordination compounds, where ligands and the central atom or ion are named in a prescribed order, sometimes with oxidation states disclosed.

Historically, diverse naming practices existed until standardized rules were developed in the 20th century by IUPAC and related bodies, promoting consistency for literature, databases, and regulation.