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Sulfur dioxide

physical science Maturity 11-13 Next article →

Sulfur dioxide is a colorless gas with a very sharp smell. You might recognize this scent from a burnt match.

In science, it is a compound made of sulfur and oxygen. It is a bent molecule with a specific shape. This gas is quite important because it plays many roles on Earth and in space. It can be helpful to humans, but it is also somewhat toxic if breathed in for a long time.

Sulfur-dioxide-resonance-2D
Sulfur-dioxide-resonance-2D

This gas is created through several different ways. A major natural source is volcanic activity. When volcanoes erupt, they can release millions of tons of the gas at once.

20180519 USGS Leilani Estates Hawaii Volcanic EruptionDSC 0411 medium
20180519 USGS Leilani Estates Hawaii Volcanic EruptionDSC 0411 medium

People also make it by burning elemental sulfur. This process creates a lot of heat. Scientists can actually use this heat to make steam and electricity. Other ways it is made include roasting certain ores or making cement.

Volcanic injection
Volcanic injection

Humans have used this gas for a very long time. Medieval alchemists called it the "volatile spirit of sulfur." In more recent history, it has been used to make sulfuric acid. This is a very important chemical for many jobs. In the United States in 1979, people used 23.6 million metric tons of it to make acid.

Estimates of past and future SO2 global anthropogenic emissions
Estimates of past and future SO2 global anthropogenic emissions

This was much more than the 150,000 metric tons used for other tasks.

We can find sulfur dioxide all over our solar system. On Earth, it is only found in very small amounts in the air. However, on the moon Io, it makes up 90% of the atmosphere.

Io Aurorae color
Io Aurorae color

On the planet Venus, it is the third-most common gas. It reacts with water there to form clouds of sulfurous acid. Even the James Webb Space Telescope has found it on a distant planet called WASP-39b.

Physical Drivers of climate change
Physical Drivers of climate change

This gas is very useful for keeping things fresh. It is used as a preservative for dried fruits like figs and apricots. It helps them stay colorful and stops them from rotting.

Cheletropic reaction of butadiene with SO2
Cheletropic reaction of butadiene with SO2

Winemakers have used it since the time of the Romans. They found that burning sulfur candles in wine jars kept the liquid from turning into vinegar. It acts as an antibiotic to stop bacteria from spoiling the wine. It can even be used to clean winery equipment with a mix of water and acid.

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🖼️ Images & Media (12)
File:Sulfur-dioxide-resonance-2D.svg
Sulfur-dioxide-resonance-2D.svg
File:Io Aurorae color.jpg
Io Aurorae color.jpg
03. Горење на сулфур во атмосфера од кислород.webm
File:Cheletropic reaction of butadiene with SO2.svg
Cheletropic reaction of butadiene with SO2.svg
File:Preparation of m-trifluoromethylbenzenesulfonyl chloride.svg
Preparation of...
File:20180519 USGS Leilani Estates Hawaii Volcanic EruptionDSC 0411 medium.jpg
20180519 USGS Leilani Estates Hawaii...
File:Volcanic injection.svg
Volcanic injection.svg
File:Acid rain woods1.JPG
Acid rain woods1.JPG
File:Estimates of past and future SO2 global anthropogenic emissions.png
Estimates of past and future SO2 global...
File:Global sulphur dioxide (SO₂) emissions by world region, OWID.svg
Global sulphur dioxide (SO₂) emissions by...
File:Physical Drivers of climate change.svg
Physical Drivers of climate change.svg
File:SPICE SRM overview.jpg
SPICE SRM overview.jpg
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