A laboratory technician tests three samples from a metal-recovery process. The samples contain copper(II) ions, iron(II) ions and iron(III) ions, with a different metal ion in each sample.
The technician adds sodium hydroxide solution to each sample.
| Sample | Observation |
|---|---|
| A | A blue precipitate forms |
| B | A brown precipitate forms |
| C | A green precipitate forms |
Identify the sample that contains iron(III) ions. Explain how the results for the other two samples support your answer.
Write the ionic equation for the reaction between the metal ion in the sample identified in part (a) and hydroxide ions.
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.