Selenic acid


Selenic acid

Chembox new
Name = Selenic acid
ImageFile = Selenic-acid-2D.png ImageName = Selenic acid
ImageFile1 = Selenic-acid-3D-vdW.png ImageName1 = Selenic acid
IUPACName = Selenic(VI) acid
OtherNames = Selenic acid
Section1 = Chembox Identifiers
SMILES = OSe(O)(=O)O
CASNo = 7783-08-6
ChemSpiderID = 1058
RTECS = VS6575000

Section2 = Chembox Properties
Formula = H2SeO4
MolarMass = 144.9734 g/mol
Appearance = Colorless deliquescent crystals
Density = 2.95 g/cm3, solid
Solubility = 130 g/100 mL (30 °C)
MeltingPt = 58 °C (331 K)
BoilingPt = 260 °C (533 K) (decomposes)
pKa = similar to H2SO4
RefractIndex = 1.5174 (D-line, 20 °C)

Section3 = Chembox Structure
MolShape = tetrahedral at Se
CrystalStruct =
Dipole =

Section7 = Chembox Hazards
ExternalMSDS =
MainHazards = Corrosive, highly toxic
NFPA-H = 3
NFPA-R = 2 | Other=OX
NFPA-F = 0
RPhrases = 23/25-33-50/53
SPhrases = 20/21-28-45-60-61

Section8 = Chembox Related
OtherAnions = selenate
OtherCations = selenyl ion, SeO22+
OtherCpds = Sulfuric acid
Selenium dioxide

Selenic acid is the chemical compound with the formula H2SeO4. This oxoacid is more descriptively written (HO)2SeO2, which emphasises that Se is attached to four oxygen atoms. As predicted by VSEPR theory, the selenium center is tetrahedral.

Preparation and reactions

Selenic acid is prepared by oxidation of selenium dioxide with hydrogen peroxide::SeO2 + H2O2 → H2SeO4To obtain the anhydrous acid as a crystalline solid, the resulting solution is evaporated at temperatures<140 °C in vacuum.Seppelt, K. “Selenoyl difluoride” Inorganic Syntheses, 1980, volume XX, pp. 36-38. ISBN 0-471-07715-1. The report describes the synthesis of selenic acid.]

Like sulfuric acid, selenic acid is a strong acid that is hygroscopic and extremely soluble in water. Concentrated solutions are viscous. Crystalline mono- and di-hydrates are known. Unlike sulfuric acid, H2SeO4 is a sufficiently strong oxidizer to liberate chlorine from chloride ions, being reduced to selenious acid (selenic [IV] acid).

Selenic acid reacts with barium salts to precipitate BaSeO4, analogous to the sulfate. Calcium selenate is however more soluble than the sulfate.

Treatment of selenic acid with fluorosulfuric acid gives the dioxydifluoride (b.p. -8.4C)::H2SeO4 + 2 HO3SF → SeO2F2 + 2 H2SO4

Hot selenic acid is capable of dissolving gold.

:2Au + 6H2SeO4 → Au2(SeO4)3 + 3H2SeO3 + 3H2O

References


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Look at other dictionaries:

  • selenic acid — n. a colorless, crystalline acid, H2SeO4, resembling sulfuric acid in its action …   English World dictionary

  • selenic acid — selenato rūgštis statusas T sritis chemija formulė H₂SeO₄ atitikmenys: angl. selenic acid rus. селеновая кислота ryšiai: sinonimas – seleno rūgštis sinonimas – vandenilio tetraoksoselenatas (2–) …   Chemijos terminų aiškinamasis žodynas

  • selenic acid — noun a strong acid (H2SeO4) analogous to sulfuric acid • Hypernyms: ↑acid …   Useful english dictionary

  • selenic acid — Chem. a crystalline, water soluble, strong, corrosive, dibasic acid, H2SeO4, resembling sulfuric acid. [1810 20] * * * …   Universalium

  • selenic acid — noun a solid white acid, HSeO, having the same structure and similar reactions as sulphuric acid …   Wiktionary

  • selenic acid — /səˌlinɪk ˈæsəd/ (say suh.leenik asuhd) noun a strong, corrosive, dibasic acid, H2SeO4, analogous to sulphuric acid …   Australian English dictionary

  • selenic — SELÉNIC, Ă, selenici, ce, adj. Care conţine seleniu. Acid selenic. – Din fr. sélénique. Trimis de LauraGellner, 21.07.2004. Sursa: DEX 98  SELÉNIC adj. v. lunar. Trimis de siveco, 13.09.2007. Sursa: Sinonime  selénic adj …   Dicționar Român

  • Sulfuric acid — Sulfuric acid …   Wikipedia

  • Telluric acid — Telluric acid …   Wikipedia

  • selenous acid — noun the oxoacid HSeO; the selenium analogue of sulfurous acid See Also: selenic acid, selenite …   Wiktionary


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