Sulfur dioxide - Wikipedia

**Properties**
General
Name	Sulfur dioxide
Chemical formula	S O₂
Appearance	Colourless gas
Physical
Formula weight	64.1 amu
Melting point	198 K (-75 °C)
Boiling point	263 K (-10 °C)
Density	1.4 ×10³ kg/m³ (liquid)
Solubility	9.4 g in 100g water
Thermochemistry
Δ_fH⁰_gas	-296.84 kJ/mol
Δ_fH⁰_liquid	? kJ/mol
Δ_fH⁰_solid	? kJ/mol
S⁰_{gas, 1 bar}	248.21 J/mol·K
S⁰_{liquid, 1 bar}	? J/mol·K
S⁰_solid	? J/mol·K
Safety
Ingestion	Relatively low toxicity, may cause nausea and vomiting. Long term hazards known.
Inhalation	Extreme irritation.
Skin	Hazardous when cryogenic or compressed.
Eyes	Hazardous when cryogenic or compressed.
More info	Hazardous Chemical Database (http://ull.chemistry.uakron.edu/erd/chemicals/8/7111.html)
SI units were used where possible. Unless otherwise stated, standard conditions were used. Disclaimer and references

Sulfur dioxide (spelt in British English Sulphur dioxide) has the chemical formula S O₂. The gas is irritant to the lungs.

It is produced by volcanoes and in various industrial processes. In particular, poor-quality coal and petroleum contains sulfur compounds, and generates sulfur dioxide when burned: the gas reacts with water and atmospheric oxygen to form sulfuric acid (H₂S O₄) - and thus Acid rain.

Sulfur dioxide is frequently used as a food additive: particularly as a preservative in alcoholic drinks.