Which of the following is used as a catalyst in contact process?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → \(V_2O_5\)
Transition metals and their compounds act as catalysts because they can change their oxidation states easily and provide a surface on which reactants are held. In the Contact process for sulphuric acid, sulphur dioxide is oxidised to sulphur trioxide over vanadium(V) oxide:
\( \displaystyle \ce{2SO2(g) + O2(g)} \xrightarrow{\ce{V2O5}} \ce{2SO3(g)} \)
The \( \ce{SO3} \) is absorbed in sulphuric acid to give oleum, which is diluted to the acid. So the catalyst is \( \ce{V2O5} \).
NCERT (2026-27 edition):
Catalytic Properties
