IUPAC nomenclature of inorganic chemistry

In chemical nomenclature, the IUPAC nomenclature of inorganic chemistry is a systematic method of naming inorganic chemical compounds, as recommended by the International Union of Pure and Applied Chemistry (IUPAC).

It is published in Nomenclature of Inorganic Chemistry (which is informally called the Red Book).

However, for the sake of brevity, even professional chemists will use the non-systematic name almost all of the time, because caffeine is a well-known common chemical with a unique structure.

Similarly, H2O is most often simply called water in English, though other chemical names do exist.

The positive ion retains its element name whereas for a single non-metal anion the ending is changed to -ide.

This system has partially fallen out of use, but survives in the common names of many chemical compounds: the modern literature contains few references to "ferric chloride" (instead calling it "iron(III) chloride"), but names like "potassium permanganate" (instead of "potassium manganate(VII)") and "sulfuric acid" abound.

In the case of cations with a +4 oxidation state, the only acceptable format for the Roman numeral 4 is IV and not IIII.

Monatomic anions: Polyatomic ions: Hydrates are ionic compounds that have absorbed water.

As the IUPAC Red Book 2005 page 69 states, "The final vowels of multiplicative prefixes should not be elided (although 'monoxide', rather than 'monooxide', is an allowed exception because of general usage)."

In writing formulas, ammonia is NH3 even though nitrogen is more electronegative (in line with the convention used by IUPAC as detailed in Table VI of the red book).