O-LevelChemistryStoichiometry5070/11 · May/June 2022 · Q141 Mark

The relative molecular mass, Mr, of liquid Z is 60. Z contains 40.0% carbon, 6.70% hydrogen and 53.3% oxygen. Which row shows the correct empirical and molecular formulae of Z?

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ACH2O; CH2O

BCH2O; C2H4O2

CC2H4O2; C2H4O2

DCH3O; C2H6O2

✓ Correct answer

B: CH2O; C2H4O2

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Topic: Stoichiometry, O-Level Chemistry (syllabus 5070). Multiple choice, 1 mark.
Source: O-Level Chemistry, May/June 2022 Paper 1 Variant 1, question 14.

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