FACTOID # 15: A mere 0.8% of West Virginians were born in a foreign country.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Oxidation number

The oxidation number of a central atom in a coordination compound is the charge that it would have if all the ligands were removed along with the electron pairs that were shared with the central atom.[1] It is used in the nomenclature of inorganic compounds. It is represented by a Roman numeral; the plus sign is omitted for positive oxidation numbers. The oxidation number is placed either as a right superscript to the element symbol, e.g. FeIII, or in parentheses after the name of the element, e.g. iron(III): in the latter case, there is no space between the element name and the oxidation number. In chemistry, the oxidation state is an indicator of the degree of oxidation of an atom in a chemical compound. ... complex In chemistry, a complex is a structure composed of a central metal atom or ion, generally a cation, surrounded by a number of negatively charged ions or neutral molecules possessing lone pairs. ... In chemistry, a ligand is an atom, ion, or molecule (see also: functional group) that generally donates one or more of its electrons through a coordinate covalent bond to, or shares its electrons through a covalent bond with, one or more central atoms or ions (these ligands act as a... A lone pair is an electron pair without bonding or sharing with other atoms. ... Inorganic nomenclature is a systematic way of naming inorganic compounds. ... The system of Roman numerals is a numeral system originating in ancient Rome, and was adapted from Etruscan numerals. ...


The oxidation number is usually numerically equal to the oxidation state. However, in a few cases the ligand atom can be less electronegative than the central atom (e.g., in iridium phosphine complexes), resulting in a formal oxidation state that is different from the oxidation number. In chemistry, the oxidation state is an indicator of the degree of oxidation of an atom in a chemical compound. ...


Spectroscopic oxidation states

Although formal oxidation numbers can be helpful for classifying compounds, they are unmeasureable and their physical meaning can be ambiguous. Formal oxidation numbers require particular caution for molecules where the bonding is covalent, since the formal oxidation numbers require the heterolytic removal of ligands, which essentially denies covalency. Spectroscopic oxidation states, as defined by Jorgenson and reiterated by Wieghart, are measureables that are bench-marked using spectroscopic and crystallographic data.[2] In chemistry, heterolysis (from Greek ἑτερος, heteros, different, and λυσις, lusis, loosening) is chemical bond cleavage of a neutral molecule generating a cation and an anion. ... In chemistry, a ligand is an atom, ion, or molecule (see also: functional group) that generally donates one or more of its electrons through a coordinate covalent bond to, or shares its electrons through a covalent bond with, one or more central atoms or ions (these ligands act as a... Covalent bonding is a description of chemical bonding that is characterized by the sharing of pairs of electrons between atoms. ...


References

  1. ^ International Union of Pure and Applied Chemistry. "oxidation number". Compendium of Chemical Terminology Internet edition.
  2. ^ Bill, E.; Bothe, E.; Chaudhuri, P.; Chlopek, K.; Herebian, D.; Kokatam, S.; Ray, K.; Weyhermueller, T.; Neese, F.; Wieghardt, K., "Molecular and electronic structure of four- and five-coordinate cobalt complexes containing two o-phenylenediamine- or two o-aminophenol-type ligands at various oxidation levels: An experimental, density functional, and correlated ab initio study", Chemistry--A European Journal, 2005, 11, 204-224.

  Results from FactBites:
 
Oxidation state - Wikipedia, the free encyclopedia (825 words)
In chemistry, the oxidation state is a measure of the degree of oxidation of an atom in a chemical compound.
The increase in oxidation state of an atom is known as an oxidation: a decrease in oxidation state is known as a reduction.
The algebraic sum of oxidation states of all atoms in a neutral molecule must be zero, while in ions the algebraic sum of the oxidation states of the constituent atoms must be equal to the charge on the ion.
EXERCISE 13-1 Oxidation and Reduction (433 words)
The oxidation number of nitrogen in nitrogen monoxide (nitric oxide) is:
The oxidation number of nitrogen in nitrite is:
The oxidation number of chromium in dichromate is:
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m