DP Chemistry (last assessment 2024)

Question 20N.2.sl.TZ0.b(vi)

Date	November 2020	Marks available	[Maximum mark: 1]	Reference code	20N.2.sl.TZ0.b(vi)
Level	sl	Paper	2	Time zone	TZ0
Command term	Deduce	Question number	b(vi)	Adapted from	N/A

b(vi).

[Maximum mark: 1]

20N.2.sl.TZ0.b(vi)

Chlorine undergoes many reactions.

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

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

Deduce, referring to oxidation states, whether ${MnO}_{2}$ is an oxidizing or reducing agent.

[1]

Markscheme

oxidizing agent AND oxidation state of $Mn$ changes from $+ 4$ to $+ 2$ /decreases ✔

Examiners report

Less than half of the candidates were awarded the mark. Some did identify MnO2 as the oxidizing agent but did not give the explanation in terms of oxidation state as required in the question. Other candidates did not have an understanding of oxidizing and reducing agents.

Syllabus sections

Core

Core » Topic 9: Redox processes » 9.1 Oxidation and reduction

Core » Topic 9: Redox processes

Question 20N.2.sl.TZ0.b(vi)

Select a Test

Syllabus sections

Confirm action