# Iron reacts with hydrochloric acid. The reaction produces iron(II) chloride and hydrogen gas. A student carries out this reaction using 0.5 mol of iron and an excess of hydrochloric acid. Explain what is meant by the term 'limiting reactant' and identify the limiting reactant in this reaction, giving a reason for your answer.

> Eduqas A-Level Chemistry — 3.5 Aromatic chemistry (A-Level only) · Explain · 5 marks

> The balanced equation for the reaction is: Fe + 2HCl → FeCl₂ + H₂

## Mark scheme (5 marks)

1. The limiting reactant is the reactant that is completely used up
2. The limiting reactant limits the amount of products formed
3. Iron is the limiting reactant
4. Because iron is not in excess / hydrochloric acid is in excess
5. Once all the iron is used up, the reaction stops / no more product can be formed

## Key terms

- [limiting reactant](https://www.gradenine.co.uk/glossary/limiting-reactant)
- [excess](https://www.gradenine.co.uk/glossary/excess)

## Related

- [Revision notes for Eduqas A-Level Chemistry](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)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/iron-reacts-with-hydrochloric-acid-the-ac81f83f) · Published by Druglandscape Ltd.