View source for Sodium hexanitritocobaltate(III)

{{chembox
| Verifiedfields = changed
| verifiedrevid = 464400670
| Name =
| ImageFile1 = Na3Co(NO2)6.svg
| ImageFile2 = Sodium hexanitritocobaltate(III) powder.jpg
| IUPACName = Sodium hexanitritocobaltate(III)
| OtherNames = Sodium cobaltinitrite
| SystematicName =
| Section1 = {{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 13198283
| EINECS = 237-077-7
| InChI = 1/Co.6NO2.3Na/c;6*2-1-3;;;/q-3;;;;;;;3*+1/rCoN6O12.3Na/c8-2(9)1(3(10)11,4(12)13,5(14)15,6(16)17)7(18)19;;;/q-3;3*+1
| InChIKey = IMBXIBFCGMYSME-PEVTYUNUAJ
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/Co.6NO2.3Na/c;6*2-1-3;;;/q-3;;;;;;;3*+1
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = IMBXIBFCGMYSME-UHFFFAOYSA-N
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo=13600-98-1
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = XO0NGY9EY7
| PubChem= 16211641
| SMILES = [Na+].[Na+].[Na+].O=[N+]([O-])[Co-3]([N+]([O-])=O)([N+](=O)[O-])([N+]([O-])=O)([N+]([O-])=O)[N+]([O-])=O
}}
| Section2 = {{Chembox Properties
| Formula = {{chem2|Na3[Co(NO2)6]}}
| Co=1|N=6|Na=3|O=12
| Appearance=Yellow crystals
| Density= 2.565 g/cm<sup>3</sup>
| MeltingPt=
| BoilingPt=
| Solubility=
 }}
| Section3 = {{Chembox Hazards
| ExternalSDS = [http://hazard.com/msds/mf/baker/baker/files/s3434.htm JT Baker MSDS]
| FlashPt=
| AutoignitionPt =
| GHS_ref=<ref>{{cite web |title=C&L Inventory |url=https://echa.europa.eu/information-on-chemicals/cl-inventory-database/-/discli/details/44858 |website=echa.europa.eu}}</ref>
| GHSPictograms = {{GHS03}}{{GHS07}}{{GHS08}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|272|315|317|319|334|335|351}}
| PPhrases = {{P-phrases|}}
 }}
| Section4 =
| Section5 =
| Section6 =
}}
'''Sodium hexanitritocobaltate(III)''' is an [[inorganic compound]] with the formula {{chem2|Na3[Co(NO2)6]}}. The anion of this yellow-coloured salt consists of the [[transition metal nitrite complex]] {{chem2|[Co(NO2)6](3-)}}. It was a reagent for the qualitative test for [[potassium]] and [[ammonium]] ions.<ref name=G&W>{{Greenwood&Earnshaw2nd}}</ref>

==Synthesis and reactions==
The compound is prepared by oxidation of cobalt(II) salts in the presence of [[sodium nitrite]]:<ref>{{cite encyclopedia|first=O. |last=Glemser |title=Sodium Hexanitritocobaltate(III) |encyclopedia=Handbook of Preparative Inorganic Chemistry |edition=2nd |editor-first=G. |editor-last=Brauer |publisher=Academic Press |date=1963 |location=New York, NY |volume=1 |page=1541}}</ref>
:{{chem2|4 [Co(H2O)6](NO3)2 + O2 + 24 NaNO2 → 4 Na3[Co(NO2)6] + 8 NaNO3 + 4 NaOH + 22 H2O}}

==Application for analysis of potassium==
Although the sodium cobaltinitrite is soluble in water, it forms the basis of a quantitative determination of potassium, thallium, and ammonium ions. Under the recommended reaction conditions the insoluble double salt, {{chem2|K2Na[Co(NO2)6]*H2O}} is precipitated and weighed.<ref name = "Vogel">{{cite book|first=A. I. |last=Vogel|date=1951 |title=Quantitative Inorganic Analysis |edition=2nd|publisher=Longmans Green and Co.}}</ref>{{pn|date=February 2024}} In [[geochemistry|geochemical analysis]], sodium cobaltinitrite is used to distinguish alkali feldspars from plagioclase feldspars in thin section.<ref name="Bailey & Stevens">{{Cite journal |last=Bailey |first=E. H. |last2=Stevens |first2=R. E. |date=1960 |title=Selective staining of K-feldspar and plagioclase on rock slabs and thin sections |url=https://pubs.geoscienceworld.org/msa/ammin/article-abstract/45/9-10/1020/541675/Selective-staining-of-K-feldspar-and-plagioclase |journal=American Mineralogist |volume=45 |pages=1020–1025 |issn=1945-3027}}</ref>
{{Gallery
|style=
|File:Sodium hexanitritocobaltate(III) solution.jpg
|Concentrated aqueous solution of sodium cobaltinitrite.
|File:Impure dipotassium sodium cobaltinitrite (K2Na(Co(NO2)6)) monohydrate.jpg
|{{chem2|K2Na[Co(NO2)6]*H2O}}
}}

[[File:EntryWithCollCode280729.png|thumb|Fragment of the {{chem2|Na3Co(NO2)6}} lattice, highlighting the {{chem2|CoN6}} and {{chem2|NaO6}} coordination spheres.<ref>{{cite journal|journal=Acta Crystallographica Section C|title=Na<sub>3</sub>Co(NO<sub>2</sub>)<sub>6</sub> at 293 and 10 K|author=Brian N. Figgis |author2=Alexandre N. Soboleva |volume =57|issue=Pt 8| year=2001|pages=885–886|doi=10.1107/S0108270101007995|pmid=11498599}}</ref>]]

==See also==
* [[Potassium hexanitritocobaltate(III)]]

==References==
{{reflist}}
{{Sodium compounds}}

[[Category:Cobalt complexes]]
[[Category:Sodium compounds]]
[[Category:Chemical tests]]
[[Category:Inorganic compounds]]
[[Category:Coordination complexes]]
[[Category:Nitrites]]