O-LevelChemistryStoichiometry5070/11 · May/June 2025 · Q11 Mark

Four gases are listed. 1 CH4 2 NH3 3 CO2 4 N2 What is the order of their rate of diffusion at room temperature and pressure?

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A1 2 4 3

B2 1 3 4

C3 4 2 1

D4 1 3 2

✓ Correct answer

C: 3 4 2 1

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Topic: Stoichiometry, O-Level Chemistry (syllabus 5070). Multiple choice, 1 mark.
Source: O-Level Chemistry, May/June 2025 Paper 1 Variant 1, question 1.

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