The key step in the manufacturing of `H_(2)SO_(4)` by contact process is

Options

A. Absorption of `SO_(3)` in `H_(2)SO_(4)` to give oleum
B. dilution of oleum with water
C. Burning of sulphur in air to generate `SO_(2)`
D. Catalytic oxidating of `SO_(2)` with `O_(2)` to give `SO_(3)`

Answer

D

Explanation

Catalytic oxidation of `SO_(2)` with `O_(2)` to form `SO_(3)` is the important step in the manufacture of `H_(2)SO_(4)` by contact process.