A student places some pondweed in a beaker of water next to a lamp. Bubbles of gas are given off by the pondweed. The student collects the gas in an upside-down test tube filled with water.
Name the gas given off by the pondweed.
Name the process in plants that produces this gas.
Describe the chemical test for this gas. Give the result.
Name the gas that plants take in from the air during this process.
The student does the same test on a test tube of air. The result is negative. Explain why.
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.