The table shows four stages in the preparation of a pure, dry sample of copper(II) sulfate crystals from copper(II) oxide and dilute sulfuric acid.
| Stage | Process |
|---|---|
| 1 | Filter the mixture to remove the unreacted copper(II) oxide. |
| 2 | Leave the concentrated solution to cool and crystallise, then dry the crystals with filter paper. |
| 3 | Add excess copper(II) oxide to warm dilute sulfuric acid and stir. |
| 4 | Heat the filtrate in an evaporating basin until crystals start to form. |
Which is the correct order for the stages?
3,4,1,23, 4, 1, 23,4,1,2
3,1,4,23, 1, 4, 23,1,4,2
1,3,4,21, 3, 4, 21,3,4,2
1,4,3,21, 4, 3, 21,4,3,2
8 exam-style questions on OCR GCSE Chemistry Practical skills. Each one has a worked solution and a mark scheme showing where the marks go.