Question

Why the sulphur trioxide, obtained during the contact process cannot be directly absorbed in water

Answer 1

When dissolved in water, Sulphur trioxide forms a “mist” of sulfuric acid, which can be difficult to store and handle. Because of this, in order to form sulfuric acid, an intermediate called “oleum” must be formed, where SO3 is dissolved  in H2SO4, giving H2S2O7. This is then dissolved in water  to form sulfuric acid.


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