Potassium pyrosulfate
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IUPAC name
dipotassium (sulfonatooxy)sulfonate
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Other names
Potassium pyrosulphate; potassium disulfate
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Identifiers | |
3D model (
JSmol ) |
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ChemSpider | |
ECHA InfoCard
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100.029.288 |
EC Number |
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PubChem CID
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UNII | |
CompTox Dashboard (EPA)
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Properties | |
K2O7S2 | |
Molar mass | 254.31 g·mol−1 |
Density | 2.28 g/cm3 |
Melting point | 325 °C (617 °F; 598 K) |
25.4 g/100 mL (20 °C) | |
Hazards | |
GHS labelling: | |
Danger | |
H314, H331 | |
P260, P261, P264, P271, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P311, P321, P363, P403+P233, P405, P501 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Potassium pyrosulfate, or potassium disulfate, is an inorganic compound with the chemical formula K2S2O7.
Production
Potassium pyrosulfate is obtained by the thermal decomposition of other salts, most directly from potassium bisulfate:[1]
- 2 KHSO4 → K2S2O7 + H2O
Temperatures above 600°C further decompose potassium pyrosulfate to potassium sulfate and sulfur trioxide however:[2]
- K2S2O7 → K2SO4 + SO3
Other salts, such as potassium trisulfate,[3] can also decompose into potassium pyrosulfate.
Chemical structure
Potassium pyrosulfate contains the
dichromate-like structure. The geometry can be visualized as a tetrahedron with two corners sharing the SO4 anion's configuration and a centrally bridged oxygen atom.[4] A semi-structural formula for the pyrosulfate anion is O3SOSO32−. The oxidation state
of sulfur in this compound is +6.
Uses
Potassium pyrosulfate is used in analytical chemistry; samples are fused with potassium pyrosulfate, (or a mixture of potassium pyrosulfate and potassium fluoride) to ensure complete dissolution prior to a quantitative analysis.[5][6]
The compound is also present in a
catalyst in conjunction with vanadium(V) oxide in the industrial production of sulfur trioxide.[7]
See also
References
- ^ Washington Wiley, Harvey (1895). Principles and Practice of Agricultural Analysis: Fertilizers. Easton, PA.: Chemical Publishing Co. p. 218. Retrieved 31 December 2015.
Potassium disulfate.
- ^ Iredelle Dillard Hinds, John (1908). Inorganic Chemistry: With the Elements of Physical and Theoretical Chemistry. New York: John Wiley & Sons. p. 547. Retrieved 31 December 2015.
Potassium disulfate.
- ISBN 9780323161299.
- .
- .
- .
- ^ Burkhardt, Donald (1965). "Sulfur trioxide production, US3362786A". Google Patents. Retrieved 31 December 2015.