# Explain why transition metals are often used as catalysts in industrial processes. Give two properties of transition metals that make them suitable for this role, and for each property give one example.

> AQA GCSE Chemistry (8462) — 4.1.3 Properties of transition metals (Chem only) · Explain · 4 marks

> Transition metals and their compounds are widely used as catalysts in the chemical industry.

## Mark scheme (4 marks)

1. Transition metals can form ions with different charges / oxidation states (variable oxidation states)
2. This allows them to transfer electrons / accept and donate electrons during reactions (enabling catalytic activity)
3. Correct named example of a transition metal used as a catalyst, e.g. iron in the Haber process / nickel in the hydrogenation of vegetable oils / vanadium(V) oxide in the Contact process
4. Transition metals have high melting points / are hard and strong, making them durable under the harsh conditions (high temperatures / pressures) of industrial processes

## Key terms

- [transition metals](https://www.gradenine.co.uk/glossary/transition-metals)
- [catalyst](https://www.gradenine.co.uk/glossary/catalyst)

## Related

- [Revision notes for AQA GCSE Chemistry (8462)](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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