Chemistry 0620 · IGCSE · Rate of reaction

Rate of reaction — practice question

A student carries out an investigation into the decomposition of hydrogen peroxide when manganese(IV) oxide is used as a catalyst. $\text{2H}_2\text{O}_2(aq) \rightarrow \text{2H}_2\text{O}(l) + \text{O}_2(g)$
(a)[2]

State what the term catalyst means.

(b(i))[1]

Suggest why the mass of the flask and its contents falls as time passes.

(b(ii))[2]

Describe how the rate of reaction changes as time passes.

(c(i))[3]

Explain, in terms of particle collisions, why the reaction rate is greater at a higher temperature.

(c(ii))[2]

Draw a line on the graph in (b) for the experiment run at a higher temperature.

Worked solution & mark scheme

This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “speeds up a reaction / raises the rate” …

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