A chemical manufacturer needs to identify a solution after its label is damaged. Records show that the solution contains one of these compounds.
| Possible compound |
|---|
| copper(II) chloride |
| copper(II) bromide |
| iron(II) chloride |
| iron(III) bromide |
A few drops of sodium hydroxide solution are added to one portion of the solution. A blue precipitate forms.
Explain how this result narrows down the possible compounds. Suggest a further test on a separate portion of the solution and explain how both possible results would identify the compound.
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.