Question

In which stage of the contact process is Oleum ($H_2{S}_2{O}_7$) obtained?

• A. First stage in the burner
• B. Second stage in the converter
• C. Third stage in the absorption tower
• D. Fourth stage in the dilution tank

Answer 1

The correct option is C Third stage in the absorption tower

Oleum ($H_2{S}_2{O}_7$) is a mixture of sulphuric acid and sulphurous acid. It is obtained in the third stage of contact process when sulphur trioxide $\left(S{O}_3\right)$ is absorbed by sulphuric acid ($H_{2}S{O}_4$) in the absorption tower.