O-LevelChemistryStoichiometry5070/11 · May/June 2020 · Q141 Mark

Ethanol can be made by the reaction shown. C2H5Br + NaOH → C2H5OH + NaBr If 5.00 g of C2H5Br produces 1.59 g of ethanol, what is the molar percentage yield of ethanol? [Mr: C2H5Br, 109; C2H5OH, 46]

A13%

B32%

C42%

D75%

✓ Correct answer

D: 75%

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Topic: Stoichiometry, O-Level Chemistry (syllabus 5070). Multiple choice, 1 mark.
Source: O-Level Chemistry, May/June 2020 Paper 1 Variant 1, question 14.

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