Two unlabeled gas cylinders contain gas mixtures, X and Y. One mixture has a composition similar to Earth's early atmosphere, while the other is similar to today's atmosphere.
A student performs tests on both mixtures and records the results in the table below:
| Test | Result with Gas Mixture X | Result with Gas Mixture Y |
|---|---|---|
| Bubble the gas through limewater | Rapidly forms a white precipitate (within 5 seconds) | Slowly forms a faint white precipitate (after 3 minutes) |
| Place a burning wooden splint into the gas | The splint is extinguished immediately | The splint continues to burn |
Explain, using the data in the table, which gas mixture represents the Earth's early atmosphere.
97 exam-style questions on Edexcel GCSE Chemistry 9.2 Earth and atmospheric science, covering 9.2.1 The Earth's early atmosphere, 9.2.2 How the atmosphere evolved, 9.2.3 Chemical test for oxygen, and 9.2.4 The greenhouse effect and climate change. Each one has a worked solution and a mark scheme showing where the marks go.