# A student carries out qualitative analysis on two unknown solutions, Solution A and Solution B. Solution A gives a brick-red flame colour during a flame test. When sodium hydroxide solution is added to Solution B, a blue precipitate forms. Explain what these observations tell the student about the metal ions present in each solution.

> Edexcel GCSE Chemistry (1CH0) — 9.1 Qualitative analysis: tests for ions (Chem only) · Explain · 4 marks

## Mark scheme (4 marks)

1. Solution A contains calcium ions (Ca²⁺)
2. The brick-red flame colour indicates the presence of calcium ions / the flame test identifies the metal cation by the colour produced
3. Solution B contains copper ions (Cu²⁺)
4. The blue precipitate forms because copper ions react with hydroxide ions / sodium hydroxide solution is used to identify metal cations by the colour of the precipitate formed

## Key terms

- [flame test](https://www.gradenine.co.uk/glossary/flame-test)
- [qualitative analysis](https://www.gradenine.co.uk/glossary/qualitative-analysis)
- [precipitate](https://www.gradenine.co.uk/glossary/precipitate)
- [metal ions](https://www.gradenine.co.uk/glossary/metal-ions)

## Related

- [Revision notes for Edexcel GCSE Chemistry (1CH0)](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-carries-out-qualitative-analysis-c6eeecb7) · Published by Druglandscape Ltd.