# A chemical company produces ammonia using a reversible reaction carried out in a closed system. The engineers increase the concentration of nitrogen gas fed into the reactor. Explain what happens to the position of equilibrium and the concentrations of the reactants and products after this change.

> OCR GCSE Chemistry A: Gateway Science (J248) — C5.2 Controlling reactions · Explain · 4 marks

> Nitrogen and hydrogen react together in a reversible reaction to form ammonia. The reaction is carried out in a closed system so that dynamic equilibrium can be established.

## Mark scheme (4 marks)

1. The position of equilibrium shifts in the forward direction / towards the products (ammonia)
2. This is because the system acts to counteract / oppose the increase in concentration of nitrogen (Le Chatelier's principle)
3. The concentration of ammonia (products) increases
4. A new equilibrium is reached where the concentrations of reactants and products remain constant (but are different from before)

## Key terms

- [closed system](https://www.gradenine.co.uk/glossary/closed-system)
- [position of equilibrium](https://www.gradenine.co.uk/glossary/position-of-equilibrium)
- [concentration](https://www.gradenine.co.uk/glossary/concentration)

## Related

- [Revision notes for OCR GCSE Chemistry A: Gateway Science (J248)](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/a-chemical-company-produces-ammonia-using-72b6046a) · Published by Druglandscape Ltd.