# A student prepares two separate solutions: a 0.1 mol/dm³ solution of sulfuric acid and a 0.1 mol/dm³ solution of ethanoic acid. Explain why the sulfuric acid solution has a lower pH than the ethanoic acid solution, despite both solutions having the same concentration.

> AQA A-Level Chemistry (7405) — 3.1.12 Acids and bases (A-Level only) · Explain · 5 marks

## Mark scheme (5 marks)

1. Sulfuric acid is a strong acid
2. Ethanoic acid is a weak acid
3. Strong acids completely / fully dissociate in water to produce hydrogen ions (H⁺ / H₃O⁺)
4. Weak acids only partially dissociate / establish an equilibrium in solution, so fewer H⁺ ions are produced
5. The greater concentration of H⁺ ions in the sulfuric acid solution results in a lower pH

## Key terms

- [pH](https://www.gradenine.co.uk/glossary/ph)

## Related

- [Revision notes for AQA A-Level Chemistry (7405)](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-student-prepares-two-separate-solutions-c732a0df) · Published by Druglandscape Ltd.