Oxidizing agent: Difference between revisions

Jump to navigation Jump to search
No edit summary
 
m (Robot: Automated text replacement (-{{SIB}} +, -{{EH}} +, -{{EJ}} +, -{{Editor Help}} +, -{{Editor Join}} +))
 
Line 1: Line 1:
{{SI}}
{{SI}}
{{EH}}
 


[[Image:Hazard O.svg|left|thumb|250px|European Union Chemical hazard symbol for oxidizing agents]]
[[Image:Hazard O.svg|left|thumb|250px|European Union Chemical hazard symbol for oxidizing agents]]
Line 107: Line 107:
[[Category:Oxidizing agents|*]]
[[Category:Oxidizing agents|*]]


{{SIB}}
 


[[de:Oxidationsmittel]]
[[de:Oxidationsmittel]]

Latest revision as of 14:38, 20 August 2012

WikiDoc Resources for Oxidizing agent

Articles

Most recent articles on Oxidizing agent

Most cited articles on Oxidizing agent

Review articles on Oxidizing agent

Articles on Oxidizing agent in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Oxidizing agent

Images of Oxidizing agent

Photos of Oxidizing agent

Podcasts & MP3s on Oxidizing agent

Videos on Oxidizing agent

Evidence Based Medicine

Cochrane Collaboration on Oxidizing agent

Bandolier on Oxidizing agent

TRIP on Oxidizing agent

Clinical Trials

Ongoing Trials on Oxidizing agent at Clinical Trials.gov

Trial results on Oxidizing agent

Clinical Trials on Oxidizing agent at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Oxidizing agent

NICE Guidance on Oxidizing agent

NHS PRODIGY Guidance

FDA on Oxidizing agent

CDC on Oxidizing agent

Books

Books on Oxidizing agent

News

Oxidizing agent in the news

Be alerted to news on Oxidizing agent

News trends on Oxidizing agent

Commentary

Blogs on Oxidizing agent

Definitions

Definitions of Oxidizing agent

Patient Resources / Community

Patient resources on Oxidizing agent

Discussion groups on Oxidizing agent

Patient Handouts on Oxidizing agent

Directions to Hospitals Treating Oxidizing agent

Risk calculators and risk factors for Oxidizing agent

Healthcare Provider Resources

Symptoms of Oxidizing agent

Causes & Risk Factors for Oxidizing agent

Diagnostic studies for Oxidizing agent

Treatment of Oxidizing agent

Continuing Medical Education (CME)

CME Programs on Oxidizing agent

International

Oxidizing agent en Espanol

Oxidizing agent en Francais

Business

Oxidizing agent in the Marketplace

Patents on Oxidizing agent

Experimental / Informatics

List of terms related to Oxidizing agent


European Union Chemical hazard symbol for oxidizing agents
Dangerous goods label for oxidizing agents
Error creating thumbnail: File missing
Oxidizing agent placard

An oxidizing agent (also called an oxidant or oxidizer) can be defined as either:

  1. a chemical compound that readily transfers oxygen atoms, or
  2. a substance that gains electrons in a redox chemical reaction

The former definition is not applicable to what most people read about, but it is the sense in which most organic chemists use the term. In both cases, the oxidizing agent becomes reduced in the process.

In simple terms:

  • The oxidizing agent is reduced.
  • The reducing agent is oxidized.
  • All atoms in a molecule can be assigned an oxidation number. This number changes when an oxidant acts on a substrate.
  • Redox reactions occur when electrons are exchanged.

A mnemonic for differentiating the reactions is "OIL RIG": Oxidation Is Loss, Reduction Is Gain (of electrons) or "LEO the lion says GER" (Lose Electrons: Oxidation, Gain Electrons: Reduction)

Example of oxidation

The formation of iron(III) oxide;

4Fe + 3O2 → 2Fe2O3

In the above equation, the Iron (Fe) has an oxidation number of 0 before and 3+ after the reaction. For oxygen (O) the oxidation number began as 0 and decreased to 2−. These changes can be viewed as two "half-reactions" that occur concurrently:

  1. Oxidation Half Reaction: Fe0 → Fe3+ + 3e
  2. Reduction Half Reaction: O2 + 4e → 2 O2−

Iron III (Fe) has been oxidized because the oxidation number increased and is the reducing agent because it gave electrons to the oxygen (O). Oxygen (O) has been reduced because the oxidation number has decreased and is the oxidizing agent because it took electrons from iron (Fe)

Alternate meanings

Because the process of oxidation is so widespread (explosives, chemical synthesis, corrosion), the term oxidizing agent has acquired multiple meanings.

One definition, an oxidizing agent receives - or accepts - electrons from a reagent. In this context, the oxidizing agent is called an electron acceptor. A classic oxidizing agent is the ferrocenium ion [Fe(C5H5)2]+ which accepts an electron to form Fe(C5H5)2. Of great interest to chemists are the details of the electron transfer event, which can be described as inner sphere or outer sphere.

In another more colloquial usage, an oxidizing agent transfers oxygen atoms to the substrate. In this context, the oxidizing agent can be called an oxygenation reagent or oxygen-atom transfer agent. Examples include [MnO4] permanganate, [CrO4]2− chromate, OsO4 osmium tetroxide, and especially ClO4 perchlorate. Notice that these species are all oxides, and in fact, polyoxides. In some cases, these oxides can also serve as electron acceptors, as illustrated by the conversion of [MnO4] to [MnO4]2−, manganate.

The strict dangerous goods definition of an oxidizing agent are substances that, while in themselves not necessarily combustible, may, generally by yielding oxygen, cause, or contribute to, the combustion of other material. (Australian Dangerous Goods Code 6th Edition) By this definition some materials that are classified as oxidizing agents by analytical chemists are not classified as oxidizing agents in a dangerous goods sense. An example is potassium dichromate which does not pass the dangerous goods test of an oxidizing agent.

Common oxidizing agents

Common oxidizing agents and their products

Agent Product(s)
O2 oxygen Various including oxides, H2O, or CO2
O3 ozone Various including ketones and aldehydes, H2O, see ozonolysis
F2 fluorine F
Cl2 chlorine Cl
Br2 bromine Br
I2 iodine I, I3
ClO hypochlorite Cl, H2O
ClO3 chlorate Cl, H2O
HNO3 nitric acid NO nitric oxide
NO2 nitrogen dioxide
Hexavalent chromium
CrO3 chromium trioxide
CrO42− chromate
Cr2O72− dichromate
Cr3+, H2O
MnO4 permanganate
MnO42− manganate
Mn2+ (acidic) or MnO2 (basic)
H2O2, other peroxides Various including oxides, H2O

See also


de:Oxidationsmittel eo:Oksidenzo et:Oksüdeerija lt:Oksidatorius nl:Oxidator

Template:WH Template:WikiDoc Sources