Elements stoichiometric names

IR-5.2 Stoichiometric names of elements and binary compounds IR-5.3 Names of ions and radicals IR-5.3.1 General IR-5.3.2 Cations IR-5.3.2.1 General IR-5.3.2.2 Monoatomic cations IR-5.3.2.3 Homopolyatomic cations IR-5.3.2.4 Heteropolyatomic cations IR-5.3.3 Anions IR-5.3.3.1 Overview IR-5.3.3.2 Monoatomic anions IR-5.3.3.3 Homopolyatomic anions IR-5.3.3.4 Heteropolyatomic anions IR-5.4 Generalized stoichiometric names... 

The simplest type of compositional name is a stoichiometric name, which is just a reflection of the empirical formula (Section IR-4.2.1) or the molecular formula (Section IR-4.2.2) of the compound. In stoichiometric names, proportions of constituent elements may be indicated in several ways, using multiplicative prefixes, oxidation numbers or charge numbers. 

Homopolyatomic cations are named by adding the charge number to the stoichiometric name of the corresponding neutral species, i.e. the element name with the appropriate multiplicative prefix. Radical dots may be added to indicate the presence of unpaired electrons. 

The following generalized stoichiometric names, based only on single-element constituents, do not carry information about the structure. 

Where an element symbol occurs in the first column, the unmodified element name is listed in the second and diird columns. The unmodified name is generally used when the element appears as an electropositive constituent in the construction of a stoichiometric name (Sections IR-5.2 and IR-5.4). Names of homoatomic cations consisting of the element are also constructed using the element name, adding multiplicative prefixes and charge numbers as applicable (Sections IR-5.3.2.1 to IR-5.3.2.3). The sections mentioned refer to parts of Nomenclature of Inorganic Chemistry. lUPAC Recommendations 2005, see above. 

Thus, aU hyphens in the table are true parts of the names. The symbols > and < placed next to an element symbol both denote two single bonds connecting the atom in question to two other atoms. For a given compound, the various systematic names, if applicable, are given in the order stoichiometric names, substitutive names, additive names and hydrogen names. Acceptable names that are not entirely systematic (or not formed according to any of the systems mentioned above) are given at the end after a semicolon. No order of preference is implied by the order in which formulae and names are listed. Reprinted by permission of lUPAC. 

Stoichiometric Proportions. The stoichiometric proportions of the constituents in a formula may be denoted by Greek numerical prefixes mono-, di-, tri-, tetra-, penta-, hexa-, hepta-, octa-, nona- (Latin), deca-, undeca- (Latin), dodeca-,. . . , icosa- (20), henicosa- (21),. . . , tri-conta-(30), tetraconta-(40),. . . , hecta-(100), and so on, preceding without a hyphen the names of the elements to which they refer. The prefix mono can usually be omitted occasionally hemi-(1/2) and sesqui- (%) are used. No elisions are made when using numerical prefixes except in the case of icosa- when the letter i is elided in docosa- and tricosa-. Beyond 10, prefixes may be replaced by Arabic numerals. 

Arsenic Pentasulphide, As2S5.—When arsenic is fused with an excess of sulphur the product contains arsenic, sulphur and arsenic pentasulphide the last-named may be extracted with liquid ammonia 8 or, by careful fractionation, the arsenic and sulphur may be removed, leaving the sulphide. If the elements are fused together in stoichiometric proportions, a greenish-yellow plastic mass is obtained which gradually hardens and becomes lemon-yellow if this product is powdered and digested with aqueous ammonia, a yellow solution results and insoluble sulphur remains. After filtering, the addition of an acid to the yellow solution precipitates the pentasulphide. 

Step 3 List Stoichiometric Coefficients, Exponents, and Charges List stoichiometric coefficients, exponents, and charges in equations based on the previously identified reaction equations and equilibria. Most of them are listed in an array form. For any two-dimensional (notone-dimensional) array, for example, AR(I,J), the I index is in rows, and the J index is in columns. The orders of elements and fluid species must be the same as those in which their names are listed in the EQBATCH input file, EQIN. However, there are several exceptions in the example presented in Appendix C of the UTCHEM Technical Manual. For the exchange equilibrium constants (Table C.13), exponents (Table C.14), and valence differences on the matrix (Table C.1S), the order is Ca-Na, Mg-Na, and H-Na. 

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