Sodium pyrosulfate
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IUPAC name
Disodium disulfate
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Other names
Sodium pyrosulphate; Disulfuric acid disodium salt, disodium disulfate; Sodium metabisulfate
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Identifiers | |
3D model (
JSmol ) |
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ChEMBL | |
ChemSpider | |
ECHA InfoCard
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100.034.190 |
EC Number |
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PubChem CID
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CompTox Dashboard (EPA)
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Properties | |
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) |
hydrolyses[2] | |
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 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 the dehydration of sodium bisulfate:[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]
See also
References
- ^ a b Olsen, J. C., ed. (1934). Van Nostrand's Chemical Annual. London: Chapman and Hall.
- .
- ISBN 978-3527306732.
- ^ Noyes, William (1913). A Textbook of Chemistry. New York: Henry Holt and Company. p. 186. Retrieved 13 January 2016.
- ISBN 9783527303854.
- ISBN 9780250399192.
- .