Chemistry · Oct / Nov 2023 · Paper 11 · Question 17

A student plans to investigate how the rate of the reaction changes when hydrochloric acid and calcium carbonate react. CaCO3(s) + 2HCl(aq) → CaCl2(aq) + H2O(l) + CO2(g) Three methods are described. 1: Record the mass of the flask and contents every 30 seconds for 5 minutes. 2: Measure and record the volume of gas in the syringe after 30 seconds. 3: Count and record the total number of bubbles of gas in the water every 30 seconds for 5 minutes. Which methods could be used to measure how the rate of reaction changes?

1. A1, 2 and 3
2. B1 and 2 only
3. C1 and 3 only
4. D2 and 3 only

As printed in the paper