A technician examines gas sample R collected from a sealed reaction chamber. The gases that may be present are oxygen and carbon dioxide.
| Test carried out on a separate portion of sample R | Observation |
|---|---|
| A glowing splint is lowered into a test tube containing the gas | The splint relights |
| The gas is bubbled through limewater | The limewater remains clear |
The technician uses these results to claim that sample R contains both oxygen and carbon dioxide. Which judgement about this claim is correct?
Only the carbon dioxide claim is supported: the clear limewater identifies carbon dioxide, but the relit splint gives no evidence for oxygen.
Only the oxygen claim is supported: the relit splint identifies oxygen, but the clear limewater gives no evidence for carbon dioxide.
Both claims are supported: the relit splint identifies oxygen and the clear limewater identifies carbon dioxide.
Neither claim is supported: the relit splint gives no evidence for oxygen and the clear limewater rules out carbon dioxide.
89 exam-style questions on AQA GCSE Chemistry 8.2 Identification of common gases, covering 8.2.1 Test for hydrogen, 8.2.2 Test for oxygen, 8.2.3 Test for carbon dioxide, and 8.2.4 Test for chlorine. Each one has a worked solution and a mark scheme showing where the marks go.