Sodium selenate

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Sodium selenate
Natriumselenat.svg
Names
IUPAC name
Sodium selenate
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.033.169 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 236-501-8
PubChem CID
RTECS number
  • VS6650000
UNII
UN number 2630
  • InChI=1S/2Na.H2O4Se/c;;1-5(2,3)4/h;;(H2,1,2,3,4)/q2*+1;/p-2
    Key: MHQOTKLEMKRJIR-UHFFFAOYSA-L
  • InChI=1S/2Na.H2O4Se/c;;1-5(2,3)4/h;;(H2,1,2,3,4)/q2*+1;/p-2
  • [O-][Se](=O)(=O)[O-].[Na+].[Na+]
Properties
Na2O4Se
Molar mass 188.947 g·mol−1
AppearanceWhite or grey powder
Density 3.098 g/cm3
soluble
Pharmacology
A12CE01 ( WHO )
Hazards
GHS labelling:
GHS-pictogram-skull.svg GHS-pictogram-silhouette.svg GHS-pictogram-pollu.svg
Danger
H301, H331, H373, H410
NFPA 704 (fire diamond)
NFPA 704.svgHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
4
0
0
Flash point Non-flammable
Related compounds
Other anions
Sodium sulfate
Other cations
Potassium selenate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Sodium selenate is the inorganic compound with the formula Na
2SeO
4, not to be confused with sodium selenite. It exists as the anhydrous salt, the heptahydrate, and the decahydrate. [1] These are white, water-soluble solids. The decahydrate is a common ingredient in multivitamins and livestock feed as a source of selenium. The anhydrous salt is used in the production of some glass. Although the selenates are much more toxic, many physical properties of sodium selenate and sodium sulfate are similar. [2]

Production

Sodium selenate is produced by oxidation of selenium, first with nitric acid, producing selenous acid. The selenous acid is neutralized to form sodium selenite. The sodium selenite is oxidized in a basic medium hydrogen peroxide to form a selenate, which is then spray-dried. [3]

Se + 2HNO3 → H2SeO3 + NO + NO2
H2SeO3 + Na2CO3 → Na2SeO3 + H2O + CO2
Na2SeO3 + H2O2 → Na2SeO4 + H2O.

It was prepared shortly after the discovery of selenium by Jöns Jacob Berzelius in 1817.

Industrial uses

Glass manufacturing

One of the earliest applications of sodium selenate was in the glass industry. Selenium produces a red hue in glass. The molten glass is treated with sodium selenate and then arsenic trioxide to reduce the compound and provide elemental selenium. Sodium selenate is also used as a decolorizing agent in glass production. The red hue it gives glass is complementary to the green hue given by ferrous oxides in the manufacturing process. When used together, the two compound produce a colourless glass. [4]

Pesticide

Sodium selenate is a common ingredient in some insecticides used against mites, aphids, and mealybugs. For most insects, a dose of 10 mg/kg is enough to be fatal. [5] [6] It is also used in some fungicides.

Bio-fortification of crops

Sodium selenate is effectively used for bio-fortification of crops hence fortifying food/feed to mitigate selenium deficiency in humans and livestock. It can be applied as foliar spray or via rooting medium e.g. added in fertilizers.

Dietary supplement

Chosen for its selenium content and high solubility, sodium selenate is a common ingredient in over-the-counter vitamin supplements. Selenium is a trace essential element. Sodium selenate and selenite are also common in premix animal feed. Neither compound has demonstrated a difference in the amount of selenium absorbed. The US FDA regulates that animal feed contain no more than 5 ppm selenium content. [7] Controversy arose in 2009 when a group of 21 polo horses died from selenium poisoning from an incorrectly mixed dietary supplement. [8]

Toxicology

The US FDA and European Union currently classify sodium selenate as toxic, primarily if ingested or inhaled. Testing on rats showed a dose of 1.6 mg/kg to be lethal. A low lethal dose as this places the chemical as being 2 to 3 times more toxic than sodium cyanide. As such, it is extremely toxic and must be handled with care. For a 70 kilograms (150 lb) person, this dosage corresponds to 112 mg, or, in terms of 200 µg pills, 560 pills. Chronic exposure to sodium selenate can cause severe lung, kidney, and liver damage. [9]

Overexposure to selenium in the diet leads to a condition known as selenosis. Selenosis occurs at blood levels greater than 100 µg/dL. Symptoms include gastrointestinal upsets, hair loss, white blotchy nails, garlic breath odour, fatigue, irritability, and mild nerve damage. [10]

Related Research Articles

<span class="mw-page-title-main">Selenium</span> Chemical element, symbol Se and atomic number 34

Selenium is a chemical element; it has symbol Se and atomic number 34. It is a nonmetal with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, and also has similarities to arsenic. It seldom occurs in its elemental state or as pure ore compounds in Earth's crust. Selenium was discovered in 1817 by Jöns Jacob Berzelius, who noted the similarity of the new element to the previously discovered tellurium.

<span class="mw-page-title-main">Borax</span> Boron compound, a salt of boric acid

Borax and tincar ) is a salt, a hydrated or anhydrous borate of sodium, with the chemical formula Na2H20B4O17. It is a colorless crystalline solid that dissolves in water to make a basic solution.

<span class="mw-page-title-main">Magnesium sulfate</span> Chemical compound with formula MgSO4

Magnesium sulfate or magnesium sulphate is a chemical compound, a salt with the formula MgSO4, consisting of magnesium cations Mg2+ (20.19% by mass) and sulfate anions SO2−4. It is a white crystalline solid, soluble in water but not in ethanol.

<span class="mw-page-title-main">Sodium sulfate</span> Chemical compound with formula Na2SO4

Sodium sulfate (also known as sodium sulphate or sulfate of soda) is the inorganic compound with formula Na2SO4 as well as several related hydrates. All forms are white solids that are highly soluble in water. With an annual production of 6 million tonnes, the decahydrate is a major commodity chemical product. It is mainly used as a filler in the manufacture of powdered home laundry detergents and in the Kraft process of paper pulping for making highly alkaline sulfides.

The selenate ion is SeO2−
4.

Selenic acid is the inorganic compound with the formula H2SeO4. It is an oxoacid of selenium, and its structure is more accurately described as O2Se(OH)2. It is a colorless compound. Although it has few uses, one of its salts, sodium selenate is used in the production of glass and animal feeds.

<span class="mw-page-title-main">Iron(II) hydroxide</span> Chemical compound

Iron(II) hydroxide or ferrous hydroxide is an inorganic compound with the formula Fe(OH)2. It is produced when iron(II) salts, from a compound such as iron(II) sulfate, are treated with hydroxide ions. Iron(II) hydroxide is a white solid, but even traces of oxygen impart a greenish tinge. The air-oxidised solid is sometimes known as "green rust".

<span class="mw-page-title-main">Selenium dioxide</span> Chemical compound

Selenium dioxide is the chemical compound with the formula SeO2. This colorless solid is one of the most frequently encountered compounds of selenium.

<span class="mw-page-title-main">Selenite (ion)</span> Anion composed of selenium and oxygen

Selenite refers to the anion with the chemical formula SeO2−3. It is the oxyanion of selenium. It is the selenium analog of the sulfite ion, SO2−3. Thus selenite is pyramidal and selenium is assigned oxidation state +4. Selenite also refers to compounds that contains this ion, for example sodium selenite Na2SeO3 which is a common source of selenite. Selenite also refers to the esters of selenous acid, for example dimethyl selenite (CH3)2SeO3.

<span class="mw-page-title-main">Selenous acid</span> Chemical compound

Selenous acid is the chemical compound with the formula H2SeO3. Structurally, it is more accurately described by O=Se(OH)2. It is the principal oxoacid of selenium; the other being selenic acid.

<span class="mw-page-title-main">Sodium molybdate</span> Chemical compound

Sodium molybdate, Na2MoO4, is useful as a source of molybdenum. This white, crystalline salt is often encountered as the dihydrate, Na2MoO4·2H2O.

<span class="mw-page-title-main">Sodium selenite</span> Chemical compound

Sodium selenite is the inorganic compound with the formula Na2SeO3. This salt is a colourless solid. The pentahydrate Na2SeO3(H2O)5 is the most common water-soluble selenium compound.

<span class="mw-page-title-main">Selenium compounds</span> Chemical compounds containing selenium

Selenium compounds are compounds containing the element selenium (Se). Among these compounds, selenium has various oxidation states, the most common ones being −2, +4, and +6. Selenium compounds exist in nature in the form of various minerals, such as clausthalite, guanajuatite, tiemannite, crookesite etc., and can also coexist with sulfide minerals such as pyrite and chalcopyrite. For many mammals, selenium compounds are essential. For example, selenomethionine and selenocysteine are selenium-containing amino acids present in the human body. Selenomethionine participates in the synthesis of selenoproteins. The reduction potential and pKa (5.47) of selenocysteine are lower than those of cysteine, making some proteins have antioxidant activity. Selenium compounds have important applications in semiconductors, glass and ceramic industries, medicine, metallurgy and other fields.

Selenite may refer to:

<span class="mw-page-title-main">Sodium selenide</span> Chemical compound

Sodium selenide is an inorganic compound of sodium and selenium with the chemical formula Na2Se.

Selenium yeast is a feed additive for livestock, used to increase the selenium content in their fodder. It is a form of selenium currently approved for human consumption in the EU and Britain. Inorganic forms of selenium are used in feeds. Since these products can be patented, producers can demand premium prices. It is produced by fermenting Saccharomyces cerevisiae in a selenium-rich media.

<span class="mw-page-title-main">Selenium in biology</span> Use of Selenium by organisms

Selenium is an essential micronutrient for animals, though it is toxic in large doses. In plants, it sometimes occurs in toxic amounts as forage, e.g. locoweed. Selenium is a component of the amino acids selenocysteine and selenomethionine. In humans, selenium is a trace element nutrient that functions as cofactor for glutathione peroxidases and certain forms of thioredoxin reductase. Selenium-containing proteins are produced from inorganic selenium via the intermediacy of selenophosphate (PSeO33−).

<span class="mw-page-title-main">Potassium selenate</span> Chemical compound

Potassium selenate, K
2SeO
4, is an odorless, white solid that forms as the potassium salt of selenic acid.

Iron(II) selenate (ferrous selenate) is an inorganic compound with the formula FeSeO4. It has anhydrous and several hydrate forms. The pentahydrate has the structure, [Fe(H2O)4]SeO4•H2O, isomorphous to the corresponding iron(II) sulfate. Heptahydrate is also known, in form of unstable green crystalline solid.

A selenate selenite is a chemical compound or salt that contains selenite and selenate anions (SeO32- and SeO42-). These are mixed anion compounds. Some have third anions.

References

  1. ↑ Kamburov, S.; Schmidt, H.; Voigt, W.; Balarew, C. (2014). "Similarities and peculiarities between the crystal structures of the hydrates of sodium sulfate and selenate". Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials. 70 (4): 714–22. Bibcode:2014AcCrB..70..714K. doi:10.1107/S2052520614007653. PMID   25080250.
  2. ↑ Langner, Bernd E. (2005). "Selenium and Selenium Compounds". Ullmann's Encyclopedia of Industrial Chemistry. Wiley. doi:10.1002/14356007.a23_525. ISBN   3527306730.
  3. ↑ USpatent 4605544,Björnberg, Arne; Martensson, Ulf S.& Paulsson, Karin M.,"Method for producing selenium salts",issued 1986-08-12
  4. ↑ Whitaker, Milton C. (1912-07-01). "Selenium Glass". Journal of Industrial and Engineering Chemistry. 7 (4): 539–540. doi:10.1021/ie50043a031.
  5. ↑ Krieger, K. (2001). Handbook of Pesticide Toxicology. Vol. 1. San Diego, California: Academic Press.
  6. ↑ Hanson, Brady; Lindblom, Stormy Dawn; Loeffler, Miriam L.; Pilon-Smits, Elizabeth A. H. (2004-04-05). "Selenium protects plants from phloem-feeding aphids due to both deterrence and toxicity". New Phytologist. 162 (3): 655–662. doi:10.1111/j.1469-8137.2004.01067.x. PMID   33873760.
  7. ↑ Podoll, K. L.; Bernard, J. B.; Ullrey, D. E.; DeBar, S. R.; Ku, P. K.; Magee, W. T. (1992-06-01). "Dietary selenate versus selenite for cattle, sheep, and horses". Journal of Animal Science. 70 (6): 1965–1970. doi:10.2527/1992.7061965x. PMID   1321804.
  8. ↑ "Officials blame mineral for horse deaths". Fort Worth Star-Telegram . Vol. 104, no. 4. 2009-04-29. p. A7. Open Access logo PLoS transparent.svg
  9. ↑ Ganther, H. E.; Baumann, C.A. (1962-08-01). "Selenium Metabolism: II. Modifying Effects of Sulfate". The Journal of Nutrition. 77 (4): 408–414. doi:10.1093/jn/77.4.408. PMID   13896696.
  10. ↑ "Selenium: Fact Sheet for Health Professionals". National Institutes of Health . 2021-03-26. Archived from the original on 2022-06-18. Retrieved 2022-06-21.{{cite web}}: CS1 maint: bot: original URL status unknown (link)
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