Chemistry 5070 · O Level · Rate of reaction

Rate of reaction — practice question

Calcium carbonate reacts with dilute hydrochloric acid. $\text{CaCO}_3(s) + 2\text{HCl}(aq) \rightarrow \text{CaCl}_2(aq) + \text{CO}_2(g) + \text{H}_2\text{O}(l)$. A student studies how the rate of this reaction changes using three different hydrochloric acid concentrations.
(a)[1]

Name the apparatus labelled E.

(b(i))[2]

Describe how to test for carbon dioxide gas.

(b(ii))[1]

Explain why the mass gets smaller as time passes.

(b(iii))[1]

State one other measurement the student could take as time passes to find the rate of this reaction.

(c)[2]

Identify two variables that ought to be kept constant in this investigation.

(d(i))[1]

Describe how the graph can be used to determine which experiment has the greatest rate.

(d(ii))[1]

Write one letter in each box on the graph to show which experiments X, Y and Z they are.

(d(iii))[1]

Describe how the graph indicates that the reactions stop.

(d(iv))[1]

Explain why the reaction comes to an end.

Worked solution & mark scheme

This 11-mark question has a full step-by-step worked solution and mark scheme. One marking point: conical flask

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