# A student investigates a gas produced during an experiment. They suspect the gas may be either chlorine or oxygen. Describe how the student could test for both chlorine and oxygen, and state the positive result for each test.

> AQA GCSE Chemistry (8462) — 4.8.2 Identification of common gases · Describe · 4 marks

## Mark scheme (4 marks)

1. Test for chlorine: hold damp litmus paper in the gas
2. Positive result for chlorine: litmus paper is bleached / turns white
3. Test for oxygen: hold a glowing splint in the gas
4. Positive result for oxygen: the glowing splint relights

## Key terms

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

## Related

- [Revision notes for AQA GCSE Chemistry (8462)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" 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-investigates-a-gas-produced-a3ebff59) · Published by Druglandscape Ltd.