O-LevelChemistryStoichiometry5070/11 · Oct/Nov 2024 · Q101 Mark

Compound X contains carbon, hydrogen and oxygen only. It has an Mr of 90. 100 g of compound X contains 40.0 g of carbon and 6.7 g of hydrogen. How many oxygen atoms are there in each molecule of compound X?

✓ Correct answer

C: 3

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

Topic: Stoichiometry, O-Level Chemistry (syllabus 5070). Multiple choice, 1 mark.
Source: O-Level Chemistry, Oct/Nov 2024 Paper 1 Variant 1, question 10.

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

For which molecules are the empirical and molecular formulae the same? 1. methanoic acid, HCO2H 2. ethanoic acid, CH3…

A 10 cm³ sample of a gaseous hydrocarbon is completely burnt in oxygen. The total volume of the products is 70 cm³. A…

Which statement most clearly indicates that diamond and graphite are forms of carbon?

Four substances have the following electrical properties. What are these four substances?

The proton number of element X is 6. The proton number of element Y is 9. What is the formula of a compound of these …

Which ion reacts with aqueous ammonia to give a precipitate that dissolves in an excess of ammonia?