Chemistry · May / June 2018 · Paper 12 · Question 25

The diagram shows three steps in the manufacture of sulfuric acid. [diagram: sulfur --step P--> sulfur dioxide --step Q--> sulfur trioxide --step R--> sulfuric acid] In which steps is a catalyst used?

1. AP, Q and R
2. BQ and R only
3. CQ only
4. DR only

As printed in the paper