A-LevelChemistryAtoms, molecules and stoichiometryOct/Nov 2022Paper 1 Q41 Mark
Calcium oxide and magnesium sulfide each react with acid. CaO(s) + 2H+(aq) → Ca²+(aq) + H2O(l) MgS(s) + 2H+(aq) → Mg2+(aq) + H2S(g) A mixture of these two compounds, X, reacts with exactly 0.125 mol of dilute hydrochloric acid. The amount of hydrogen sulfide formed is 0.0250 mol. What was the mass of calcium oxide in mixture X?
A1.4 g
B2.1 g
C2.8 g
D4.2 g
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The correct answer is B. This question tests the candidate's understanding of atoms, molecules and stoichiometry within the Chemistrysyllabus. The examiner's mark scheme requires...
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