O-LevelChemistryStoichiometry5070/12 · Oct/Nov 2023 · Q91 Mark

Which reaction would produce the greatest volume of carbon dioxide at room temperature and pressure? [Mr: CaCO3, 100; Na2CO3, 106; CuCO3, 124]

Aburning 1 g of carbon in excess oxygen C(s) + O2(g) → CO2(g)

Bthermal decomposition of 10 g of calcium carbonate in the air CaCO3(s) → CaO(s) + CO2(g)

Cadding 10 g of sodium carbonate to an excess of dilute hydrochloric acid Na2CO3(s) + 2HCl(aq) → 2NaCl(aq) + CO2(g) + H2O(l)

Dadding 50 cm³ of 1 mol/dm³ sulfuric acid to an excess of copper carbonate CuCO3(s) + H2SO4(aq) → CuSO4(aq) + CO2(g) + H2O(l)

✓ Correct answer

B: thermal decomposition of 10 g of calcium carbonate in the air CaCO3(s) → CaO(s) + CO2(g)

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Topic: Stoichiometry, O-Level Chemistry (syllabus 5070). Multiple choice, 1 mark.
Source: O-Level Chemistry, Oct/Nov 2023 Paper 1 Variant 2, question 9.

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