What is SO3? Important knowledge about SO3.

1. Definition of SO₃:

SO₃, also known as Sulfuric Anhydride, is a chemical compound of sulfur and oxygen. It is known in English as “Sulfur trioxide”. The molar mass of SO₃ is 80.0664 g/mol. The structure of SO₃ molecule consists of a central sulfur atom connected to three oxygen atoms. The ion structure of SO₃ is not clearly defined because it is a compound forming complex ions.

2. Properties of SO₃:

SO₃ in standard conditions appears as a colorless and odorless white powder. The pH of SO₃ is quite low, indicating that it is highly acidic. A particular chemical property of SO₃ is its ability to react with water to form sulfuric acid.

3. Common chemical equations involving SO₃:

SO₃ does not react directly with metals, acids or non-metals. However, it can react with salts to form sulfate salts. For example:
2NaCl + SO₃ -> Na₂SO₄ + 2Cl₂

4. Synthesis of SO₃:

In the lab, SO₃ can be synthesized by heating sulfuric acid with sulfur pentoxide:
2H₂SO₄ + S₂O₅ -> 4SO₃ + 2H₂O
On an industrial scale, SO₃ is synthesized by burning sulfur or sulfur dioxide in air:
S + O₂ -> SO₂
2SO₂ + O₂ -> 2SO₃