# The contact process is used industrially to manufacture sulfuric acid. Explain why the conditions used in the contact process represent a compromise, rather than the most extreme conditions possible.

> OCR GCSE Chemistry A: Gateway Science (J248) — C6.1 Improving processes and products · Explain · 4 marks

> Sulfuric acid is one of the most widely produced industrial chemicals in the world. It is manufactured using the contact process, which uses vanadium(V) oxide as a catalyst, a temperature of 450°C, and a pressure of 2 atm.

## Mark scheme (4 marks)

1. A higher temperature would increase the rate of reaction / speed up the reaction
2. But the reaction is reversible, so a higher temperature shifts the equilibrium towards the reactants / reduces the yield of sulfur trioxide
3. 450°C is chosen as a compromise between a sufficient rate of reaction and an acceptable yield of sulfur trioxide / product
4. The vanadium(V) oxide catalyst is used to increase the rate of reaction without affecting the yield / position of equilibrium

## Key terms

- [contact process](https://www.gradenine.co.uk/glossary/contact-process)

## Related

- [Revision notes for OCR GCSE Chemistry A: Gateway Science (J248)](https://www.gradenine.co.uk/learn)
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Source: [GradeNine](https://www.gradenine.co.uk/q/the-contact-process-is-used-industrially-532dc1fa) · Published by Druglandscape Ltd.