A student adds a few drops of sodium hydroxide solution to four solutions, A, B, C and D.
Each solution contains one metal ion.
The table shows the results.
| Solution | Colour of precipitate |
|---|---|
| A | blue |
| B | green |
| C | orange-brown |
| D | white |
Identify the metal ion in solutions A, B and C.
Solution D gives an orange-red colour in a flame test.
Identify the metal ion in solution D.
Write the ionic equation for the formation of the precipitate in solution A.
Include state symbols.
The green precipitate from solution B slowly turns orange-brown at its surface when it is left open to the air.
Suggest why. Use ideas about ions and electrons.
107 exam-style questions on OCR GCSE Chemistry 4.2 Identifying the products of chemical reactions, covering 4.2.1 Tests to identify gases, 4.2.2 Tests for aqueous ions and flame tests, and 4.2.3 Instrumental methods of analysis. Each one has a worked solution and a mark scheme showing where the marks go.