Sodium pyrosulfate

Sodium pyrosulfate^[1]
Names
	IUPAC name Disodium disulfate
	Other names Sodium pyrosulphate; Disulfuric acid disodium salt, disodium disulfate; Sodium metabisulfate
Identifiers
CAS Number	13870-29-6 ;
3D model (JSmol)	Interactive image;
ChEMBL	ChEMBL111016 ;
ChemSpider	7970254;
ECHA InfoCard	100.034.190
EC Number	237-625-5;
PubChem CID	9794487;
CompTox Dashboard (EPA)	DTXSID60889631 ;
	InChI InChI=1S/2Na.H2O7S2/c;;1-8(2,3)7-9(4,5)6/h;;(H,1,2,3)(H,4,5,6)/q2*+1;/p-2 Key: JXAZAUKOWVKTLO-UHFFFAOYSA-L;
	SMILES [Na+].[Na+].[O-]S(=O)(=O)OS(=O)(=O)[O-];
Properties
Chemical formula	Na2S2O7
Molar mass	222.12 g/mol
Appearance	Translucent white crystals
Density	2.658 g/cm3
Melting point	400.9 °C (753.6 °F; 674.0 K)
Boiling point	decomposes at 460 °C (860 °F; 733 K)
Solubility in water	hydrolyses
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Sodium pyrosulfate is an inorganic compound with the chemical formula of Na₂S₂O₇.^[1] It is a colorless salt.^[3] It hydrolyses in water to form sodium bisulfate with a chemical formula of NaHSO4 which has a pH of around 1.

Preparation

Sodium pyrosulfate is obtained by heating sodium bisulfate to 280 °C (536 °F) ^[4]^[5]

2 NaHSO₄ → Na₂S₂O₇ + H₂O

Temperatures above 460 °C further decompose the compound, producing sodium sulfate and sulfur trioxide:

Na₂S₂O₇ → Na₂SO₄ + SO₃

Applications

Sodium pyrosulfate was used in analytical chemistry. Samples are fused with sodium pyrosulfate to ensure complete dissolution before a quantitative analysis.^[6]^[7]

References

^ ^a ^b Olsen, J. C., ed. (1934). Van Nostrand's Chemical Annual. London: Chapman and Hall.
^ Heinz K. Hofmeister; John R. Van Wazer (1962). "Hydrolysis of Sodium Pyrosulfate". Inorganic Chemistry. 1 (4). ACS: 811–812. doi:10.1021/ic50004a019.
^ Helmold Plessen (2000). "Sodium Sulfates". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a24_355. ISBN 978-3527306732.
^ Noyes, William (1913). A Textbook of Chemistry. New York: Henry Holt and Company. p. 186. Retrieved 13 January 2016.
^ von Plessen, Helmold (2000). "Sodium Sulfates". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a24_355. ISBN 9783527303854.
^ Nemodruk, Aleksandr; Karalova, Zinaida (1969). Analytical chemistry of boron: Analytical chemistry of the elements. Charlottesville, VA: Ann Arbor-Humphrey Science Publishers. pp. 23 & 193. ISBN 9780250399192.
^ Kiely, P. V.; Jackson, M. L. (1965). "Quartz, Feldspar, and Mica Determination for Soils by Sodium Pyrosulfate Fusion". Soil Science Society of America Journal. 29 (2): 159–163. Bibcode:1965SSASJ..29..159K. doi:10.2136/sssaj1965.03615995002900020015x.

[Nostrand-1] Olsen, J. C., ed. (1934). Van Nostrand's Chemical Annual. London: Chapman and Hall.

[2] Heinz K. Hofmeister; John R. Van Wazer (1962). "Hydrolysis of Sodium Pyrosulfate". Inorganic Chemistry. 1 (4). ACS: 811–812. doi:10.1021/ic50004a019.

[Ull-3] Helmold Plessen (2000). "Sodium Sulfates". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a24_355. ISBN 978-3527306732.

[4] Noyes, William (1913). A Textbook of Chemistry. New York: Henry Holt and Company. p. 186. Retrieved 13 January 2016.

[5] von Plessen, Helmold (2000). "Sodium Sulfates". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a24_355. ISBN 9783527303854.

[6] Nemodruk, Aleksandr; Karalova, Zinaida (1969). Analytical chemistry of boron: Analytical chemistry of the elements. Charlottesville, VA: Ann Arbor-Humphrey Science Publishers. pp. 23 & 193. ISBN 9780250399192.

[7] Kiely, P. V.; Jackson, M. L. (1965). "Quartz, Feldspar, and Mica Determination for Soils by Sodium Pyrosulfate Fusion". Soil Science Society of America Journal. 29 (2): 159–163. Bibcode:1965SSASJ..29..159K. doi:10.2136/sssaj1965.03615995002900020015x.

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Preparation

Applications

See also

References