O-LevelBiologyRespiration5090/11 · Oct/Nov 2022 · Q171 Mark

An experiment is set up, as shown. Test-tubes 1 and 2 contain limewater. Limewater is a clear solution that turns cloudy in the presence of carbon dioxide. Air is pumped through the apparatus. What is the appearance of the limewater in test-tubes 1 and 2 after a period of 10 minutes?

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Atest-tube 1: clear, test-tube 2: clear

Btest-tube 1: clear, test-tube 2: cloudy

Ctest-tube 1: cloudy, test-tube 2: clear

Dtest-tube 1: cloudy, test-tube 2: cloudy

✓ Correct answer

B: test-tube 1: clear, test-tube 2: cloudy

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Topic: Respiration, O-Level Biology (syllabus 5090). Multiple choice, 1 mark.
Source: O-Level Biology, Oct/Nov 2022 Paper 1 Variant 1, question 17.

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