Question

Given below are some of the steps of the Contact process. Arrange them in the proper sequence of their occurrence.​

a: Dilution of oleum (${\text{H}}_2{\text{S}}_2{\text{O}}_7$)
b: Absorption of sulphur trioxide (${\text{SO}}_3$)
c: Production of sulphur dioxide (${\text{SO}}_2$)
d: Oxidation of sulphur dioxide (${\text{SO}}_2$)

Answer 1

$\bullet$ The first step in the Contact process is the production of sulphur dioxide by burning sulphur.

$\bullet$ The produced sulphur dioxide is then oxidised on a catalyst bed to produce sulphur trioxide.

$\bullet$ The sulphur trioxide is then absorbed in sulphuric acid to produce fuming sulphuric acid or oleum.

$\bullet$ Finally, the oleum is diluted with water to produce 98% concentrated sulphuric acid.

So, the correct sequence of the occurence of the steps in Contact process is:

Production of sulphur dioxide (${\text{SO}}_2$) $\to$ Oxidation of sulphur dioxide (${\text{SO}}_2$) $\to$ Absorption of sulphur trioxide (${\text{SO}}_3$) $\to$ Dilution of oleum (${\text{H}}_2{\text{S}}_2{\text{O}}_7$)