A-LevelChemistryAtoms, molecules and stoichiometry9701/12 · Oct/Nov 2021 · Q11 Mark

Compound X consists of 40.0% carbon, 6.7% hydrogen and 53.3% oxygen by mass. What is the empirical formula of compound X?

ACH2O

BC2H2O

CC2H4O

DCHO

✓ Correct answer

A: CH2O

Practise more questions on this topic

Oracle Prep sorts past-paper questions by topic, so you can drill Atoms, molecules and stoichiometry and see which topics are most likely to come up next.

About this question

Topic: Atoms, molecules and stoichiometry, A-Level Chemistry (syllabus 9701). Multiple choice, 1 mark.
Source: A-Level Chemistry, Oct/Nov 2021 Paper 1 Variant 2, question 1.

Questions and mark schemes are from past examination papers and remain the copyright of the exam board. How Oracle Prep builds its content

Related Chemistry questions

Atoms, molecules and stoichiometryFeb/Mar 201915m

It is possible that ores containing basic copper(II) carbonate also contain water of crystallisation. The formula of …

Atoms, molecules and stoichiometryFeb/Mar 20201m

Sodium azide, NaN3, decomposes as shown. 2NaN3 → 2Na + 3N2 Which volume of nitrogen, measured at room temperature and…

Atoms, molecules and stoichiometryFeb/Mar 20211m

Substance Q is a hydrocarbon. When 1.00 g of Q is completely burned, 3.22 g of carbon dioxide is produced. What could…

Halogen derivativesFeb/Mar 20211m

Dibromopentanes can undergo 'double elimination' reactions to produce hydrocarbons. 2NaOH + C₅H₁₀Br₂ → C₅H₈ + 2NaBr +…

Organic synthesisFeb/Mar 20211m

In this question you can assume that ¹H and ³H have the same chemical properties. A sample of ethanal contains only o…

Carboxylic acids and derivativesFeb/Mar 20211m

Which reaction gives butanoic acid as one of its products?

← Browse all past-paper questions