Oksidacioni agens — разлика између измена
Садржај обрисан Садржај додат
м претварање ISBN веза у шаблон |
. |
||
Ред 1:
{{short description|Hemijsko jedinjenje koje se koristi za oksidaciju druge supstance u hemijskoj reakciji}}
[[Датотека:Hazard O.svg|right|thumb|125px|Simbol za hemijske hazarde [[Evropska unija|Evropske unije]] za oksidacione agense]]
[[Датотека:Dangclass5 1.png|thumb|125px|Natpis za oksidacione agense]]
'''Oksidacioni agens''' (''oksidans'', ''oksidizer'') se može definisati kao supstanca koja uklanja [[elektron]]e sa nekog drugog reaktanta u [[оксидо-редукција|redoks]] [[hemijska reakcija|hemijskoj reakciji]].<ref name=Ullmann>{{Ullmann}}</ref> Oksidacioni agens se [[оксидо-редукција|redukuje]] preuzimanjem elektrona na sebe, dok se [[redukujući agens|reduktans]] oksiduje dajući elektrone. [[Кисеоник|Kiseonik]] je dobar primer oksidacionog agensa među mnogobrojnim drugim jedinjenjima.<ref>{{Cite book|last=Hudlický |first=Miloš |title=Reductions in Organic Chemistry |publisher=American Chemical Society |year=1996 |location=Washington, D.C.|pages=429|id={{ISBN|978-0-8412-3344-7}}}}</ref><ref>{{Cite book|last=Hudlický |first=Miloš |title=Oxidations in Organic Chemistry |publisher=American Chemical Society |year=1990|location=Washington, D.C.|pages=456|id={{ISBN|978-0-8412-1780-5}}}}</ref> Уобичајени оксиданти су [[кисеоник]], [[водоник пероксид]] и [[халоген]]и.
{{рут}}
In one sense, an oxidizing agent is a chemical species that undergoes a [[chemical reaction]] in which it gains one or more electrons. In that sense, it is one component in an [[Redox|oxidation–reduction]] (redox) reaction. In the second sense, an oxidizing agent is a chemical species that transfers electronegative atoms, usually oxygen, to a substrate. [[Combustion]], many explosives, and [[organic redox reaction]]s involve atom-transfer reactions.
==Electron acceptors==
[[file:Tetracyanoquinodimethane Formula V.1.svg|thumb|right|100px|[[Tetracyanoquinodimethane]] is an organic electron-acceptor.]]
Electron acceptors participate in [[electron-transfer reactions]]. In this context, the oxidizing agent is called an '''electron acceptor''' and the reducing agent is called an electron donor. A classic oxidizing agent is the [[Ferrocenium tetrafluoroborate|ferrocenium]] ion {{chem|Fe(C|5|H|5|)|2|+}}, which accepts an electron to form Fe(C<sub>5</sub>H<sub>5</sub>)<sub>2</sub>. One of the strongest acceptors commercially available is "[[Magic blue]]", the radical cation derived from N(C<sub>6</sub>H<sub>4</sub>-4-Br)<sub>3</sub>.<ref name=Geiger>{{cite journal|author=N. G. Connelly, W. E. Geiger| title=Chemical Redox Agents for Organometallic Chemistry|journal=[[Chemical Reviews]]|year= 1996| volume= 96|issue=2| pages= 877–910| doi=10.1021/cr940053x| pmid=11848774}}</ref>
Extensive tabulations of ranking the electron accepting properties of various reagents (redox potentials) are available, see [[Standard electrode potential (data page)]].
==Atom-transfer reagents==
In more common usage, an oxidizing agent transfers oxygen atoms to a substrate. In this context, the oxidizing agent can be called an oxygenation reagent or oxygen-atom transfer (OAT) agent.<ref>{{March6th}}</ref> Examples include {{chem|MnO|4|-}} ([[permanganate]]), {{chem|CrO|4|2-}} ([[Chromate ion|chromate]]), OsO<sub>4</sub> ([[osmium tetroxide]]), and especially {{chem|ClO|4|-}} ([[perchlorate]]). Notice that these species are all [[oxide]]s.
In some cases, these oxides can also serve as electron acceptors, as illustrated by the conversion of {{chem|MnO|4|-}} to {{chem|MnO|4|2-}}, [[manganate]].
== Dangerous materials definition ==
The [[dangerous goods]] definition of an oxidizing agent is a substance that can cause or contribute to the combustion of other material.<ref>Australian Dangerous Goods Code, 6th Edition</ref> By this definition some materials that are classified as oxidizing agents by analytical chemists are not classified as oxidizing agents in a dangerous materials sense. An example is [[potassium dichromate]], which does not pass the dangerous goods test of an oxidizing agent.
The [[U.S. Department of Transportation]] defines oxidizing agents specifically. There are two definitions for oxidizing agents governed under DOT regulations. These two are [[HAZMAT Class 5 Oxidizing agents and organic peroxides|Class 5]]; Division 5.1(a)1 and Class 5; Division 5.1(a)2. Division 5.1 "means a material that may, generally by yielding oxygen, cause or enhance the combustion of other materials." Division 5.(a)1 of the DOT code applies to solid oxidizers "if, when tested in accordance with the UN Manual of Tests and Criteria (IBR, see § 171.7 of this subchapter), its mean burning time is less than or equal to the burning time of a 3:7 potassium bromate/cellulose mixture." 5.1(a)2 of the DOT code applies to liquid oxidizers "if, when tested in accordance with the UN Manual of Tests and Criteria, it spontaneously ignites or its mean time for a pressure rise from 690 kPa to 2070 kPa gauge is less than the time of a 1:1 nitric acid (65 percent)/cellulose mixture."<ref>49 CFR 172.127 General Requirements for Shipments and Packagings; Subpart D</ref>
== Primeri oksidacije ==
Линија 15 ⟶ 36:
Kiseonik (-{O}-) je redukovan, jer je njegov oksidacioni broj umanjen. On je oksidacioni agens, jer je uzeo elektrone sa gvožđa (-{Fe}-).
=== Uobičajeni oksidacioni agensi i njihovi proizvodi ===
{| class="wikitable"
Линија 63 ⟶ 84:
== Reference ==
{{reflist|
== Literatura ==
* {{cite book |title=The Lewis acid-base concepts : an overview |last=Jensen |first=W.B.|year=1980 |publisher=Wiley |location=New York |isbn=0-471-03902-0 }}
* {{cite book| url=http://goldbook.iupac.org/html/E/E01976.html |title=electron acceptor |date=2014 |website=IUPAC Gold Book |doi=10.1351/goldbook.E01976 |isbn=978-0-9678550-9-7 |access-date=21 April 2018}}
[[Категорија:Оксидационо средство]]
| |||