DP Chemistry (last assessment 2024)

Question 20N.2.hl.TZ0.1b(iii)

b(iii).

[Maximum mark: 1]

20N.2.hl.TZ0.1b(iii)

Chlorine undergoes many reactions.

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

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

(b(iii))

Determine the excess amount, in $mol$ , of the other reactant.

[1]

Markscheme

$« 0.0307 mol \times 4 = 0.123 mol »$

$« 0.400 mol - 0.123 mol = » 0.277 « mol »$ ✔

Examiners report

Surprisingly, quite a number of candidates struggled with the quantity of excess reactant despite correctly identifying limiting reactant previously.

Syllabus sections