Two gas mixtures leave different outlets of an air-recycling unit. A technician tests each gas using a glowing splint.
| Outlet | Observation |
|---|---|
| P | The splint continues to glow but does not relight. |
| Q | The splint relights and a flame forms. |
Explain which outlet gas is much richer in oxygen than ordinary air.
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.