Question

Name the oxide of sulphur which reacts with water to give sulphuric acid.
In the contact process, the direct reaction between oxide of sulphur and water is avoided. In this process, what does the oxide of sulphur react with instead of water, and what is the name of the product?

Answer 1

Sulphur trioxide is an oxide of sulphur that reacts with water to give sulphuric acid.
The reaction is given below:

SO₃+ H₂O → H₂SO₄

In this process, sulphur dioxide reacts with sulphuric acid instead of water to produce oleum.
The reaction is given below:

SO₃ + H₂SO₄ → H₂S₂O₇