Sulfur dioxide
chemical compound
Sulfur dioxide (also sulphur dioxide) is the chemical compound with the formula SO2. It is a gas. It smells like burnt matches or rotten eggs. It can also cause suffocation. Sulfur dioxide is produced by volcanoes and in various industrial processes. It is also used to protect wine from oxygen and bacteria. It can be produced by burning sulfur. It dissolves in water to produce sulfurous acid. It can be oxidized to trioxide, which is dissolved in sulfuric acid to make more sulfuric acid. It is used to make sulfites.
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| The Lewis structure of sulfur dioxide (SO2), showing unshared electron pairs. | ||
| Names | ||
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| IUPAC name
Sulfur dioxide
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| Other names
Sulfurous anhydride
Sulfur(IV) oxide | ||
| Identifiers | ||
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3D model (JSmol)
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| Beilstein Reference | 3535237 | |
| ChEBI | ||
| ChEMBL | ||
| ChemSpider | ||
| ECHA InfoCard | 100.028.359 | |
| EC Number |
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| E number | E220 (preservatives) | |
| Gmelin Reference | 1443 | |
| KEGG | ||
| MeSH | Sulfur+dioxide | |
PubChem CID
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| RTECS number |
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| UNII | ||
| UN number | 1079, 2037 | |
CompTox Dashboard (EPA)
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| Properties | ||
| SO 2 | ||
| Molar mass | 64.066 g mol−1 | |
| Appearance | Colorless gas | |
| Odor | Pungent; similar to a just-struck match[1] | |
| Density | 2.6288 kg m−3 | |
| Melting point | −72 °C; −98 °F; 201 K | |
| Boiling point | −10 °C (14 °F; 263 K) | |
| 94 g/L[2] forms sulfurous acid | ||
| Vapor pressure | 237.2 kPa | |
| Acidity (pKa) | 1.81 | |
| Basicity (pKb) | 12.19 | |
| −18.2·10−6 cm3/mol | ||
| Viscosity | 0.403 cP (at 0 °C) | |
| Structure | ||
| C2v | ||
| Digonal | ||
| Dihedral | ||
| 1.62 D | ||
| Thermochemistry | ||
| Std enthalpy of formation ΔfH |
−296.81 kJ mol−1 | |
| Standard molar entropy S |
248.223 J K−1 mol−1 | |
| Hazards | ||
| NFPA 704 |
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| U.S. Permissible exposure limit (PEL) |
TWA 5 ppm (13 mg/m3) | |
| Related compounds | ||
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | ||
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| Infobox references | ||
Sources
change- ↑ Sulfur dioxide Archived 2019-12-30 at the Wayback Machine, U.S. National Library of Medicine
- ↑ Lide, David R., ed. (2006). CRC Handbook of Chemistry and Physics (87th ed.). Boca Raton, FL: CRC Press. ISBN 0-8493-0487-3.
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