A recycling facility has three processing streams, P, Q and R. Each stream contains a solution of one metal compound.
The three solutions contain calcium ions, magnesium ions and aluminium ions, with each ion present in one stream.
A chemist records one test result for each stream.
| Stream | Test result |
|---|---|
| P | An orange-red colour was produced in a flame test. |
| Q | Sodium hydroxide solution produced a white precipitate that remained when excess sodium hydroxide solution was added. |
| R | Sodium hydroxide solution produced a white precipitate that dissolved when excess sodium hydroxide solution was added. |
Which metal ion is present in each stream? Explain how the test results allow all three ions to be identified.
93 exam-style questions on AQA GCSE Chemistry 8.3 Identification of ions by chemical and spectroscopic means, covering 8.3.1 Flame tests, 8.3.2 Metal hydroxides, 8.3.3 Carbonates, 8.3.4 Halides, 8.3.5 Sulfates, 8.3.6 Instrumental methods, and 8.3.7 Flame emission spectroscopy. Each one has a worked solution and a mark scheme showing where the marks go.