Nomenclature systems element names

The systematic naming of an inorganic substance involves the construction of a name from entities which are manipulated in accordance with defined procedures to provide compositional and structural information. The element names (or roots derived from them or from their Latin equivalents) (Tables I and II, see also Chapter IR-3) are combined with affixes in order to construct systematic names by procedures which are called systems of nomenclature. 

Generally, nomenclature systems require a root on which to construct the name. This root can be an element name (e.g. cobalt or silicon ) for use in additive nomenclature, or can be derived from an element name (e.g. sil from silicon , plumb from plumbum for lead) and elaborated to yield a parent hydride name (e.g. silane or plumbane ) for use in substitutive nomenclature. 

If the cation and anion exist in only one common charged form, there is no ambiguity between formula and name. Sodium chloride must be NaCl, and lithium sulfide must be Li2S, so that the sum of positive and negative charges is zero. With many elements, such as the transition metals, several ions of different charge may exist. Fe ", Fe + and Cu+, Cu + are two common examples. Clearly, an ambiguity exists if we use the name iron for both Fe + and Fe + or copper for both Cu" and Cu +. Two systems have been developed to avoid this problem the Stock system and the common nomenclature system. 

It is not wise to infer the detailed physical nature of a compound from the name alone. In this system the name of the (electropositive) metal is not modified from that of the element, but the name of the electronegative element is, and in the way described in the Substitutive Nomenclature section, above. Similarly we derive oxide and sulfide, for example, from oxygen and sulfur. The same division between electronegative and electropositive parts is evident in the covalent nonionic compotmd SiC, which can be named silicon tetrachloride, though an equally valid substitutive name is tetrachlorosilane. 

Stock (nomenclature) System A system that uses Roman numerals to name elements that form more than one type of cation. (For example Fe, iron(II) Fe, iron(III).) [6.4] stoichiometry The area of chemistry that deals with the... 

The naming of alkanes and cycloalkanes in Sections 3.3 and 3.4 illustrates the application of the lUPAC system of nomenclature to these two specific classes of organic compounds. Now let us describe the general approach of the lUPAC system. The name we give to any compound with a chain of carbon atoms consists of three parts a prefix, an infix (a modifying element inserted into a word), and a suffix. Each part provides specific information about the structural formula of the compound. 

Some metal atoms, especially those of transition and inner-transition elements, form more than one type of charged ion. Copper, for example, forms both Cu and Cu, and iron forms Fe and Fe. The names of ionic compounds containing such elements must indicate which ion is present in the compound. A nomenclature system that does this well indicates the ionic charge of the metal ion by a roman numeral in parentheses following the name of the metal. Thus, CuCl is copper(l) chloride and CUCI2 is copper(ll) chloride. These names are expressed verbally as copper one chloride and copper two chloride. ... 

Table 2.5 lists some common cations of the transition elements. Most of these elements have more than one ion, so require the Stock nomenclature system or the older suffix system. A few, such as zinc, have only a single ion that is normally encountered, and you usually name them by just the metal name. You would not be wrong, however, if, for example, you named Zn as zinc(II) ion. 

Stock system a system of chemical nomenclature in which the charge on a metal atom or oxidation number of an atom is denoted by a Roman numeral in parentheses following the element name. (23)... 

In the days of alchemy and the phlogiston theory, no system of nomenclature that would be considered logical ia the 1990s was possible. Names were not based on composition, but on historical association, eg, Glauber s salt for sodium sulfate decahydrate and Epsom salt for magnesium sulfate physical characteristics, eg, spirit of wiae for ethanol, oil of vitriol for sulfuric acid, butter of antimony for antimony trichloride, Hver of sulfur for potassium sulfide, and cream of tartar for potassium hydrogen tartrate or physiological behavior, eg, caustic soda for sodium hydroxide. Some of these common or trivial names persist, especially ia the nonchemical Hterature. Such names were a necessity at the time they were iatroduced because the concept of molecular stmcture had not been developed, and even elemental composition was incomplete or iadeterminate for many substances. 

Some older systems of nomenclature are still in use. For example, some cations were once denoted by the endings -ous and -ic for the ions with lower and higher charges, respectively. To make matters worse, these endings were in some cases added to the Latin form of the element s name. Thus, iron(II) ions were called ferrous ions and iron(III) ions were called ferric ions (see Appendix 3C). We do not use this system in this text, but you will sometimes come across it and should be aware of it. 

Many hydrogen compounds are acids. Acids require a different system of nomenclature than other compounds. There are two types of acids binary acids and ternary acids. All acids include the word acid in their name. Binary acids contain only two elements one of which is hydrogen and the other a nonmetal. When naming binary acids, the prefix hydro- appears before the root name of the nonmetal, and there will be an -ic suffix. As an acid, H2S would be hydrosulfuric acid. We used H2S to illustrate the fact that there can be two possible names, hydrogen sulfide or hydrosulfuric acid. If your instructor does not specify which name to use, either is correct. Technically, the name hydrosulfuric acid only applies to aqueous solutions of H2S, H2S(aq). 

The brilliant Frenchman s legacy will be with us forever. Traite Elementaire de Chimie was the world s first real chemistry text. In it Lavoisier introduced a whole new system of nomenclature, which we still use. No longer would chemists refer to oil of vitriol or flowers of zinc. Instead they adopted names like sulfuric acid and zinc oxide, names that reflected the actual composition of the substances in question. Lavoisier clearly defined elements as substances that could not be broken down further by chemical means. Chemistry was evolving into an organized science ... 

Morveau appendices containing the nomenclature of some compound substances, which combine sometimes like simple bodies a memoir by de Fourcroy, explaining the tables of nomenclature (thirty-seven octavo pages) a directory of the new nomenclature in ninety-four pages, and the symbols prepared by Ilassenfratz and Adet, a chemical shorthand by which the names of elements and compounds could be replaced by symbols. This system never came into general use, and symbols, in so far as they were used by chemists, were of the already developed systems, until Dalton s concept of the atomic weights and symbols had been simplified by Berzelius (in 1815) into the system still in use. 

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