# The industrial manufacture of ammonia uses the reversible reaction shown. N₂(g) + 3H₂(g) ⇌ 2NH₃(g)   ΔH = −92 kJ/mol. Explain the effect on the equilibrium position and on the yield of ammonia when the pressure of the system is increased.

> Cambridge International IGCSE Chemistry (0620) — 6.3 Reversible reactions and equilibrium · Explain · 4 marks

## Mark scheme (4 marks)

1. Increasing pressure shifts the equilibrium position to the right / towards the side with fewer moles of gas
2. Because the right-hand side has fewer moles of gas (2 moles) than the left-hand side (4 moles)
3. The rate of the forward reaction increases more than the rate of the reverse reaction / system counteracts the increased pressure
4. The yield of ammonia increases

## Key terms

- [reversible reaction](https://www.gradenine.co.uk/glossary/reversible-reaction)
- [equilibrium position](https://www.gradenine.co.uk/glossary/equilibrium-position)
- [yield](https://www.gradenine.co.uk/glossary/yield)
- [pressure](https://www.gradenine.co.uk/glossary/pressure)

## Related

- [Revision notes for Cambridge International IGCSE Chemistry (0620)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/the-industrial-manufacture-of-ammonia-uses-d189a5ce) · Published by Druglandscape Ltd.