From Surf Wiki (app.surf) — the open knowledge base

Perxenate

Chemical compound

In chemistry, perxenates are salts of the yellow xenon-containing anion . This anion has octahedral molecular geometry, as determined by Raman spectroscopy, having O–Xe–O bond angles varying between 87° and 93°. The Xe–O bond length was determined by X-ray crystallography to be 1.875 Å.

Synthesis

Perxenates are synthesized by the disproportionation of xenon trioxide when dissolved in strong alkali:{{cite book :2 XeO3 (s) + 4 OH− (aq) → Xe (g) + (aq) + O2 (g) + 2 H2O (l)

When Ba(OH)2 is used as the alkali, barium perxenate can be crystallized from the resulting solution.

Perxenic acid

Perxenic acid is the unstable conjugate acid of the perxenate anion, formed by the solution of xenon tetroxide in water. It has not been isolated as a free acid, because under acidic conditions it rapidly decomposes into xenon trioxide, water, and oxygen gas: :

Its extrapolated formula, H4XeO6, is inferred from the octahedral geometry of the perxenate ion () in its alkali metal salts.

The pKa of aqueous perxenic acid has been indirectly calculated to be below 0, making it an extremely strong acid. Its first ionization yields the anion , which has a pKa value of 4.29, still relatively acidic. The twice deprotonated species has a pKa value of 10.81.{{cite book

Properties

Perxenic acid and the anion are both strong oxidizing agents, capable of oxidising silver(I), copper (II) and manganese(II) to (respectively) silver(III), copper(III), and permanganate.{{cite book | url-access = registration

The sodium, potassium, and barium salts are soluble.{{cite book : Ba2XeO6 (s) + 2 H2SO4 (l) → XeO4 (g) + 2 BaSO4 (s) + 2 H2O (l)

Most metal perxenates are stable, except silver perxenate, which decomposes violently.{{cite book

Applications

Sodium perxenate, Na4XeO6, can be used for the analytic separation of trace amounts of americium from curium. The separation involves the oxidation of Am3+ to Am4+ by sodium perxenate in acidic solution in the presence of La3+, followed by treatment with calcium fluoride, which forms insoluble fluorides with Cm3+ and La3+, but retains Am4+ and Pu4+ in solution as soluble fluorides.

References

{{Holleman&Wiberg
(March 1970). "Vibrational spectra and structures of xenate(VI) and perxenate(VIII) ions in aqueous solution". Inorganic Chemistry.
(Aug 1963). "Geometry of the Perxenate Ion". Science.
(October 1988). "Protolytic properties of perxenic acid". Inorganic Chemistry.
{{Holleman&Wiberg
(March 1965). "Analytical Oxidation of Americium with Sodium Perxenate". Analytical Chemistry.
{{Cotton&Wilkinson6th

Info: Wikipedia Source

This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page.

oxyanions salts xenon(viii)-compounds octahedral-compounds

Want to explore this topic further?

Ask Mako anything about Perxenate — get instant answers, deeper analysis, and related topics.

Research with Mako

Free with your Surf account

Content sourced from Wikipedia, available under CC BY-SA 4.0.

This content may have been generated or modified by AI. CloudSurf Software LLC is not responsible for the accuracy, completeness, or reliability of AI-generated content. Always verify important information from primary sources.

Report