A student makes three statements about identifying ions.
Statement 1: a solid containing both sodium ions and potassium ions may give only a yellow flame, because the sodium colour masks the lilac colour
Statement 2: a test is only useful for identifying an ion if no other ion that could be present gives the same result
Statement 3: a white precipitate with a few drops of sodium hydroxide solution is enough, on its own, to show that calcium ions are present
Which statements are correct?
1 only
1 and 2 only
2 and 3 only
1, 2 and 3
35 exam-style questions on Edexcel GCSE Chemistry 10.1 Qualitative analysis: tests for ions, covering 10.1.1 Principles of ion tests and flame tests, 10.1.2 Tests for cations and for ammonia, 10.1.3 Tests for anions, 10.1.4 Identification of ions in unknown salts, and 10.1.5 Instrumental methods of analysis. Each one has a worked solution and a mark scheme showing where the marks go.