|
|
| Line 1: |
Line 1: |
| {{chembox
| | Andera is what you can contact her but she [http://medialab.zendesk.com/entries/54181460-Will-You-Often-End-Up-Bored-Try-One-Of-These-Hobby-Ideas- email psychic readings] by no means truly liked that title. Mississippi [http://myfusionprofits.com/groups/find-out-about-self-improvement-tips-here/ free tarot readings] is where his house is. To perform lacross is some thing he would by no means give up. Credit authorising is how she tends to make a residing.<br><br>my blog; free psychic reading ([http://www.Prayerarmor.com/uncategorized/dont-know-which-kind-of-hobby-to-take-up-read-the-following-tips/ http://www.Prayerarmor.com/uncategorized/dont-know-which-kind-of-hobby-to-take-up-read-the-following-tips/]) |
| | verifiedrevid = 435546139
| |
| | Name = Arsenic pentoxide
| |
| | ImageFile = Arsenic-pentoxide-3D-polyhedra.png
| |
| | ImageName = Arsenic pentoxide
| |
| | OtherNames = Arsenic(V) oxide<br />Arsenic oxide<br />Arsenic anhydride
| |
| | Section1 = {{Chembox Identifiers
| |
| | InChI = 1/As2O5/c3-1(4)7-2(5)6
| |
| | SMILES = O=[As](=O)O[As](=O)=O
| |
| | InChIKey = COHDHYZHOPQOFD-UHFFFAOYAN
| |
| | StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| |
| | StdInChI = 1S/As2O5/c3-1(4)7-2(5)6
| |
| | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| |
| | StdInChIKey = COHDHYZHOPQOFD-UHFFFAOYSA-N
| |
| | CASNo_Ref = {{cascite|correct|CAS}}
| |
| | CASNo = 1303-28-2
| |
| | PubChem = 14771
| |
| | EINECS = 215-116-9
| |
| | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| |
| | ChemSpiderID = 14088
| |
| | RTECS = CG2275000
| |
| }}
| |
| | Section2 = {{Chembox Properties
| |
| | Formula = As<sub>2</sub>O<sub>5</sub>
| |
| | MolarMass = 229.8402 g/mol
| |
| | Appearance = white [[hygroscopic]] powder
| |
| | Density = 4.32 g/cm<sup>3</sup>
| |
| | MeltingPt = 315 °C (decomposes)
| |
| | BoilingPt =
| |
| | Solubility = 59.5 g/100 mL (0 °C) <br> 65.8 g/100 mL (20 °C) <br> 8.20 g/100 mL (100 °C)
| |
| | SolubleOther = soluble in [[alcohol]]
| |
| | pKa = 7
| |
| }}
| |
| | Section7 = {{Chembox Hazards
| |
| | ExternalMSDS =
| |
| | EUClass = Very toxic ('''T+''')<br />Carc. Cat. 1<br />Dangerous for the environment ('''N''')
| |
| | NFPA-H = 4
| |
| | NFPA-F = 0
| |
| | NFPA-R = 0
| |
| | RPhrases = {{R45}}, {{R23/25}}, {{R50/53}}
| |
| | SPhrases = {{S53}}, {{S45}}, {{S60}}, {{S61}}
| |
| | LD50 = 8 mg/kg (rat, oral)
| |
| }}
| |
| | Section8 = {{Chembox Other
| |
| | OtherAnions =
| |
| | OtherCations = [[Phosphorus pentoxide]]<br />[[Antimony pentoxide]]
| |
| | OtherCpds = [[Arsenic trioxide]]<br />[[Arsenic acid]]}}
| |
| }}
| |
| | |
| '''Arsenic pentoxide''' is the [[inorganic compound]] with the formula As<sub>2</sub>O<sub>5</sub>.<ref>{{Greenwood&Earnshaw2nd}}</ref> This glassy, white, [[deliquescent]] solid is relatively unstable, consistent with the rarity of the As(V) oxidation state. More common, and far more important commercially, is [[arsenic(III) oxide]] (As<sub>2</sub>O<sub>3</sub>). All arsenic compounds are highly toxic and thus find only limited commercial applications.
| |
| | |
| ==Structure==
| |
| The structure consists of tetrahedral {AsO<sub>4</sub>} and octahedral {AsO<sub>6</sub>} centres linked by sharing corners.<ref name = "Jansen">{{cite journal | author = Martin Jansen | title = Crystal Structure of As<sub>2</sub>O<sub>5</sub> | year = 1977 | journal = Angewandte Chemie International Edition in English | volume = 16 | issue = 5 | pages = 314–315 | doi = 10.1002/anie.197703142}}</ref> The structure differs from that of the corresponding phosphorus(V) oxide.
| |
| | |
| ==Synthesis==
| |
| | |
| ===Historical===
| |
| [[Paracelsus]] Macquer found a crystallizable salt which he called ‘sel neutre arsenical’. This salt was the obtaining residue after distilling [[nitric acid]] from a mixture of [[potassium nitrate]] and [[arsenic trioxide]]. Previously Paracelsus heated a mixture of arsenic trioxide and potassium nitrate. He applied the term ‘arsenicum fixum’ to the product. A. [[Libavius]] called the same product ‘butyrum arsenici’ (butter of arsenic), although this term was actually used for arsenic tricholoride. The products that Paracelsus and Libavius found were all impure alkali arsenates.<ref name = "Mellor">{{cite journal | author = J. W. Mellor | title = Comprehensive Treatise on Inorganic & Theoretical Chemistry | journal = http://www.rexresearch.com/alchemy10/melloras.htm English | volume = IX - Arsenic }}</ref> [[Scheele]] prepared a number of arsenates by the action of arsenic acid on the alkalies. One of the arsenates that he prepared, was arsenic pentoxide.<ref name = "Zenger">{{cite journal | author = C.W. Zenger et al | title = Arsenic 149 | journal = http://tera-3.ul.cs.cmu.edu/NASD/4dcb85c3-9fee-4c83-9e6d-fe6ce5522b59/China/disk4/75/75-2/31005153/HTML/00000166.htm}}</ref> The water in the alkalies evaporated at 180˚C, and the arsenic pentoxide was stable below 400˚C .<ref name = "Mellor"/>
| |
| | |
| ===Modern methods===
| |
| Arsenic pentoxide can be crystallized by heating As<sub>2</sub>O<sub>3</sub> under oxygen. This reaction is reversible:<ref name = "Jansen"/>
| |
| | |
| As<sub>2</sub>O<sub>5</sub> <math>\overrightarrow{\leftarrow}</math> As<sub>2</sub>O<sub>3</sub> + O<sub>2</sub>
| |
| | |
| Strong [[oxidizing agents]] such as [[ozone]], [[hydrogen peroxide]], and [[nitric acid]] convert arsenic trioxide to the pentoxide.
| |
| | |
| Arsenic acid can be generated via routine processing of arsenic compounds including the oxidation of arsenic and arsenic-containing minerals in air. Illustrative is the roasting of [[orpiment]], a typical arsenic sulfide ore:<ref name=Ullmann>{{Ullmann | author = Grund, S. C.; Hanusch, K.; Wolf, H. U. | title = Arsenic and Arsenic Compounds | doi = 10.1002/14356007.a03_113.pub2 }}</ref>
| |
| 2 As<sub>2</sub>S<sub>3</sub> + 11 O<sub>2</sub> → 2 As<sub>2</sub>O<sub>5</sub> + 6 SO<sub>2</sub>
| |
| | |
| ==Safety==
| |
| {{main|arsenic toxicity}}
| |
| Like all arsenic compounds, the pentoxide is highly toxic. Its reduced derivative arsenite, which is an As(III) compound, is even more toxic since it has a high affinity for thiol groups of [[cysteine]] residues in proteins.
| |
| | |
| ==References==
| |
| <references/>
| |
| | |
| ==External links==
| |
| *[http://www.cdc.gov/niosh/npg/npgd0038.html NIOSH Pocket Guide to Chemical Hazards]
| |
| *[http://www-cie.iarc.fr/htdocs/monographs/suppl7/arsenic.html IARC Monograph – Arsenic and Arsenic Compounds]
| |
| *[http://ntp.niehs.nih.gov/ntp/roc/eleventh/profiles/s015arse.pdf NTP Report on Carcinogens – Inorganic Arsenic Compounds]
| |
| *[http://esis.jrc.ec.europa.eu/ ESIS: European chemical Substances Information System]
| |
| *{{nist}}
| |
| | |
| {{Arsenic compounds}}
| |
| | |
| {{DEFAULTSORT:Arsenic Pentoxide}}
| |
| [[Category:Arsenic compounds]]
| |
| [[Category:Chalcoarsenics]]
| |
| [[Category:Oxides]]
| |
| [[Category:IARC Group 1 carcinogens]]
| |
Andera is what you can contact her but she email psychic readings by no means truly liked that title. Mississippi free tarot readings is where his house is. To perform lacross is some thing he would by no means give up. Credit authorising is how she tends to make a residing.
my blog; free psychic reading (http://www.Prayerarmor.com/uncategorized/dont-know-which-kind-of-hobby-to-take-up-read-the-following-tips/)