(a)[1]
What is meant by an excess of calcium carbonate?
(b)[2]
Name the two pieces of apparatus, A and B.
(c)[1]
The student does experiment 1 at $20\,^{\circ}\text{C}$. Name a piece of apparatus that can be used to keep the temperature constant.
(d)[2]
The student carries out two further experiments: experiment 2 at $40\,^{\circ}\text{C}$ and experiment 3 at $60\,^{\circ}\text{C}$. Suggest two variables that the student keeps constant so that temperature is the only variable affecting the rate of reaction.
(e(i))[1]
Describe how the graphs are used to decide which experiment has the fastest rate.
(e(ii))[1]
Write a number in each box on the graph to identify experiments 1, 2 and 3.
(e(iii))[1]
State how the graph shows that the reactions stop.
(e(iv))[1]
Why do the reactions stop?