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SO₂

Sulfur dioxide

IUPAC : Sulfur dioxide
OxideIndustrialFood

Colourless gas with a pungent odour, intermediate in the chemical industry (sulfuric acid) and food preservative (E220, wines, dried fruits). Main pollutant responsible for acid rain.

3D ball-and-stick representation of Sulfur dioxide (formula SO₂). Constituent atoms: S, O.
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Physical properties

Molar mass64.066 g/mol
State at 20 °Cgas
Density—
Melting point200.75 K (-72.40 °C)
Boiling point263.00 K (-10.15 °C)
Solubility (H₂O)9.4 g/100 mL à 25 °C

Structure

Crystal system—
3D render modeBall-and-stick

Uses and applications

  • Sulfuric acid synthesis (contact process: SO₂ → SO₃ → H₂SO₄)
  • Food preservative E220 (wine, dried fruits, mustard)
  • Pulp bleaching
  • Refrigerant (historical, replaced by CFCs then HFCs)
  • Indicator of atmospheric pollution

Safety (GHS)

GHS04 · Gas under pressureGHS05 · CorrosiveGHS06 · Acute toxicity
H statements : H280, H314, H331

Toxic, irritating and corrosive gas. Responsible for acid rain when emitted by power plants and industry.

Constituent elements

16S
Sulfur
8O
Oxygen

References

PubChem CID1119
CAS7446-09-5
SMILESO=S=O
Sources : PubChem CID 1119 · NIST Chemistry WebBook

Related processes

Industrial processes involving this compound.