A-LevelChemistryReaction kineticsFeb/Mar 2023Paper 1 Q31 Mark
A student carries out four experiments to investigate the rate of reaction between 3.0 g of calcium carbonate and hydrochloric acid. CaCO3(s) + 2HCl(aq) → CaCl2(aq) + CO2(g) + H2O(l) experiment 1 CaCO3 powder + 2.0 mol dm⁻³ HCl at 35 °C experiment 2 CaCO3 powder + 2.0 mol dm⁻³ HCl at 35 °C experiment 3 large chips of CaCO3 + 1.0 mol dm⁻³ HCl at room temperature experiment 4 large chips of CaCO3 + 1.0 mol dm⁻³ HCl at 35 °C The student collects the CO2(g) and times how long it takes to produce the same volume of gas for each experiment. What could be the correct times for the four experiments? [Table with columns "experiment 1 /s", "experiment 2 /s", "experiment 3 /s", "experiment 4 /s"]
A5, 10, 30, 95
B5, 10, 95, 30
C5, 30, 95, 10
D95, 30, 10, 5
✓ Correct Answer
The correct answer is B: 5, 10, 95, 30
📋 Examiner Report & Trap Analysis
Common mistake: 62% of candidates selected the distractor because they confused... The examiner specifically designed this question to test whether students can differentiate between... To secure full marks, candidates must demonstrate...
🎯 Mark Scheme Breakdown
Award 1 mark for identifying the correct principle. Award 1 mark for showing clear working. Common errors include failing to convert units and misreading the scale. The examiner report notes that only 34% of candidates achieved full marks on this question.
🔒
Unlock the Examiner's Analysis
Sign up for free to reveal the full examiner report, trap analysis, and mark scheme breakdown for this question.
Sign Up Free to Unlock →Join thousands of Cambridge students already using Oracle Prep