Stock nomenclature for
inorganic compounds is a widely used system of
chemical nomenclature developed by the German chemist
Alfred Stock
Alfred Stock (July 16, 1876 – August 12, 1946) was a German inorganic chemist. He did pioneering research on the hydrides of boron and silicon, coordination chemistry, mercury, and mercury poisoning. The German Chemical Society's Alfred-Stoc ...
and first published in 1919. In the "Stock system", the
oxidation state
In chemistry, the oxidation state, or oxidation number, is the hypothetical charge of an atom if all of its bonds to different atoms were fully ionic. It describes the degree of oxidation (loss of electrons) of an atom in a chemical compound. C ...
s of some or all of the elements in a compound are indicated in
parentheses
A bracket is either of two tall fore- or back-facing punctuation marks commonly used to isolate a segment of text or data from its surroundings. Typically deployed in symmetric pairs, an individual bracket may be identified as a 'left' or 'r ...
by
Roman numeral
Roman numerals are a numeral system that originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the Late Middle Ages. Numbers are written with combinations of letters from the Latin alphabet, ea ...
s.
Style
Contrary to the usual English style for parentheses, there is no space between the end of the element name and the opening parenthesis: for
AgF, the correct style is "silver(I) fluoride" not "silver (I) fluoride".
Where there is no ambiguity about the oxidation state of an element in a compound, it is not necessary to indicate it with Roman numerals: hence for
NaCl
Sodium chloride , commonly known as salt (although sea salt also contains other chemical salts), is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions. With molar masses of 22.99 and 35.45 g/ ...
, sodium chloride will suffice; sodium(I) chloride(−I) is unnecessarily long and such usage is very rare.
Examples
*
FeCl2: iron(II) chloride
*
FeCl3: iron(III) chloride
* : potassium manganate(VII) (rarely used except in
pre-university education; potassium
permanganate
A permanganate () is a chemical compound containing the manganate(VII) ion, , the conjugate base of permanganic acid. Because the manganese atom is in the +7 oxidation state, the permanganate(VII) ion is a strong oxidizing agent. The ion is a tr ...
is ubiquitous)
* : hexaamminecobalt(III)
Mixed-valence compounds
*
Co3O4: cobalt(II,III) oxide. Co
3O
4 is a
mixed-valence compound
Mixed valence complexes contain an element which is present in more than one oxidation state. Well-known mixed valence compounds include the Creutz–Taube complex, Prussian blue, and molybdenum blue. Many solids are mixed-valency including ...
that is more accurately described as Co
IICo
III2O
4, i.e.
o2+Co
3+]
2 2−sub>4.
*
Sb2O4: antimony(III,V) oxide. Sb
2O
4 is better formulated as Sb
IIISb
VO
4, i.e.
b3+Sb
5+]
2−sub>4.
See also
*
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 '' Nomencl ...
References
{{reflist
Chemical nomenclature