# A student notices that the burette used in a titration was not rinsed with the acid solution before being filled, but was rinsed only with distilled water. Explain how this error would affect the titre value obtained, compared with the true titre.

> Cambridge International IGCSE Chemistry (0620) — 12.2 Acid-base titrations · Explain · 4 marks

> A student completes a titration using sulfuric acid in the burette and sodium hydroxide solution in the conical flask, with methyl orange as the indicator. After the titration, the student realises the burette was rinsed with distilled water only before being filled with sulfuric acid.

## Mark scheme (4 marks)

1. The acid in the burette is diluted / the concentration of sulfuric acid in the burette is lower than intended
2. More acid would be needed to neutralise the sodium hydroxide / a larger volume of acid is required to reach the end-point
3. The titre value recorded would be larger / higher than the true titre
4. This is a systematic error, so all repeat titres would be affected in the same way / the results would not be accurate (but could be precise / concordant)

## Key terms

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

## 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/a-student-notices-that-the-burette-bf833dbd) · Published by Druglandscape Ltd.