Chemistry · May / June 2025 · Paper 11 · Question 17

The diagram shows apparatus used to investigate two different reactions that produce gases. The reactants for each experiment are mixed and the mass of flask plus contents for each experiment is recorded every 30 seconds. A graph of the mass against time is drawn. In experiment 1, solid X is calcium carbonate. In experiment 2, solid X is magnesium. Which graph is correct?

1. AGraph A: mass of flask plus contents increases, experiment 1 curve above experiment 2
2. BGraph B: mass of flask plus contents increases, experiment 2 curve above experiment 1
3. CGraph C: mass of flask plus contents decreases, experiment 2 curve above experiment 1
4. DGraph D: mass of flask plus contents decreases, experiment 1 curve above experiment 2

As printed in the paper