DP Chemistry (last assessment 2024)

Question 20N.2.hl.TZ0.b(ii)

b(ii).

[Maximum mark: 2]

20N.2.hl.TZ0.b(ii)

Chlorine undergoes many reactions.

$2.67 g$ of manganese(IV) oxide was added to $200.0 {cm}^{3}$ of $2.00 mol {dm}^{- 3} HCl$ .

${MnO}_{2} (s) + 4 HCl (aq) \to {Cl}_{2} (g) + 2 H_{2} O (l) + {MnCl}_{2} (aq)$

Determine the limiting reactant, showing your calculations.

[2]

Markscheme

$« n_{HCl} = 2.00 mol {dm}^{- 3} \times 0.2000 {dm}^{3} » = 0.400 mol$ ✔

$« \frac{0.400}{4} = » 0.100 mol$ AND ${MnO}_{2}$ is the limiting reactant ✔

Accept other valid methods of determining the limiting reactant in M2.

Examiners report

90% of candidates earned full marks on this 2-mark question involving finding a limiting reactant.

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