Study the nomenclature of inorganic chemistry.

Basics of English inorganic chemistry nomenclature

Naming binary compounds

These are compounds consisting of two elements.

The second name ends with the suffix –ide (chloride, oxide, etc.).

The formation of the whole name of the substance depends on whether or not the given binary compound contains a metal. If it contains a semimetal, the rules are the same as for metals.

When a compound contains a metal, e.g. FeCl₂, the so-called stock system is used, where the basic form of the first element (in this case iron) and the number of its oxidation state (identified by a Roman numeral) are followed by the second element ending with the suffix –ide. Thus, FeCl₂ is written as iron (II) chloride, which is read as “iron two chloride“. The older system, which today remains only in technical names, used the endings –ic or –ous, the former referring to a higher oxidation state and the latter to a lower one. Therefore, FeCl₂ could also be called ferrous chloride (compare with FeCl₃ = ferric chloride). However, this system now only prevails in the nomenclature of oxoacids and their salts and will hopefully soon disappear altogether, as it requires knowing what oxidation states the given element actually achieves before it can be used. In conclusion, endings –ous and –ic are still used in technical names, usually in the combination with the Latin name of the given element, but the stock system (which uses the English names of elements whenever possible) is strongly preferred for the systematic naming of inorganic binary compounds containing either a metal or a semimetal.

When the binary compound contains neither a metal nor a semimetal, write the basic form of both the first and the second element and use the Latin prefixes mono-, di-, tri-, etc., to express the real number of atoms (not the oxidation state!). CO₂ is therefore called carbon dioxide. Similarly, N₂O₃ is then called dinitrogen trioxide, etc.

The main difference is that if a binary compound contains a metal or a semimetal, it has Roman numerals after the name of the first element to express its oxidation state, whereas if there is no metal or semimetal in a binary compound, Latin prefixes express the real amount of atoms and are placed in front of the name of the relevant element.

Date: 2015-01-12; view: 1818