Sulfur dioxide
General
|
|
|---|---|
| Name | Sulfur dioxide |
| Chemical formula | SO2 |
| 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
|
|
| ΔfH |
-296.84 kJ/mol |
| ΔfH |
? kJ/mol |
| ΔfH |
? kJ/mol |
| S |
248.21 J/mol·K |
| S |
? J/mol·K |
| S |
? 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 |
| SI units were used where possible. Unless otherwise stated, standard conditions were used. | |
Sulfur dioxide (spelt in British English Sulphur dioxide) has the chemical formula SO2. The gas is irritant to the lungs and is often described in layman's terms as smelling of rotten eggs.
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 sulfurous acid (H2SO3) - and thus Acid rain.
Sulfur dioxide is frequently used as a food additive: particularly as a preservative in alcoholic drinks.
The word equation for acid rain is:
sulfur dioxide + water -> hydrogen sulfite
H2SO3 is also called "hydrogen sulfite".