Chemistry 0620 · IGCSE · Rate of reaction

Rate of reaction — practice question

A student studies the rate of reaction when small pieces of calcium carbonate react with an excess of hydrochloric acid at a concentration of $1\,\text{mol dm}^{-3}$. $\text{CaCO}_3(s) + 2\text{HCl}(aq) \rightarrow \text{CaCl}_2(aq) + \text{CO}_2(g) + \text{H}_2\text{O}(l)$
(a)[1]

Name the salt produced when calcium carbonate reacts with hydrochloric acid.

(b(i))[1]

State why the mass of the reaction mixture decreases.

(b(ii))[1]

Calculate the decrease in mass in the first 40 seconds of the experiment.

(b(iii))[2]

Draw a line on the grid for the run using hydrochloric acid at a concentration of $2\,\text{mol dm}^{-3}$.

(b(iv))[1]

Calculate the mass decrease when $0.50\,\text{g}$ of calcium carbonate is used.

(b(v))[1]

Complete the table by entering the sizes of the calcium carbonate pieces in the first column.

Worked solution & mark scheme

This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: the salt calcium chloride

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