Potassium sulfite
Appearance
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Names | |
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IUPAC name
Potassium sulfite
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Other names
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Identifiers | |
3D model (JSmol)
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ChemSpider | |
ECHA InfoCard | 100.030.279 |
PubChem CID
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UNII | |
CompTox Dashboard (EPA)
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Properties | |
K2SO3 | |
Molar mass | 158.26 g/mol |
Appearance | White solid |
Density | 2.49 g/cm3[1] |
Soluble | |
Acidity (pKa) | 8 |
−64.0·10−6 cm3/mol | |
Hazards | |
Flash point | Non-flammable |
Related compounds | |
Other anions
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Potassium sulfate Potassium selenite |
Other cations
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Sodium sulfite |
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 sulfite is the inorganic compound with the formula K2SO3. It is the salt of potassium cation and sulfite anion. It is a white solid that is highly soluble in water. Potassium sulfite is used for preserving food and beverages.[2]
Production and reactions
[edit]Potassium sulfite is produced by the thermal decomposition of potassium metabisulfite at 190 °C:[3]
- K2S2O5 → K2SO3 + SO2
Structure
[edit]The structure of solid K2SO3, as assessed by X-ray crystallography. The S-O distances are 1.515 Å, and the O-S-O angles are 105.2°[1]
References
[edit]- ^ a b Andersen, Leif; Strömberg, Dan; Nevala, H.; Pohjola, S.; Niinistö, Lauri; Volden, Hans V.; Weidlein, Johann; Zingaro, Ralph A. (1986). "The Structure of Potassium Sulfite". Acta Chemica Scandinavica. 40a: 479–480. doi:10.3891/acta.chem.scand.40a-0479.
- ^ "Potassium sulfite (225)". Codex Alimentarius. Food and Agriculture Organization of the United Nations.
- ^ Johnstone, H. F. (1946). "Sulfites and Pyrosulfites of the Alkali Metals". Inorganic Syntheses. Vol. 2. pp. 162–167. doi:10.1002/9780470132333.ch49. ISBN 9780470132333.