Sodium hexanitritocobaltate(III) explained

Sodium hexanitritocobaltate(III) is inorganic compound with the formula . The anion of this yellow-coloured salt consists of the transition metal nitrite complex . It was a reagent for the qualitative test for potassium and ammonium ions.

Synthesis and reactions

The compound is prepared by oxidation of cobalt(II) salts in the presence of sodium nitrite:^[1]

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, is precipitated and weighed.^[2] In geochemical analysis, sodium cobaltinitrite is used to distinguish alkali feldspars from plagioclase feldspars in thin section.^[3]

See also

• Potassium hexanitritocobaltate(III)

Notes and References

1. Encyclopedia: O. . Glemser . Sodium Hexanitritocobaltate(III) . Handbook of Preparative Inorganic Chemistry . 2nd . G. . Brauer . Academic Press . 1963 . New York, NY . 1 . 1541.
2. Book: Vogel, A. I. . 1951 . Quantitative Inorganic Analysis . 2nd. Longmans Green and Co..
3. Bailey . E. H. . Stevens . R. E. . 1960 . Selective staining of K-feldspar and plagioclase on rock slabs and thin sections . American Mineralogist . 45 . 1020–1025 . 1945-3027.