Pearson Edexcel A Level · Chemistry (9CH0)

Topic 3: Redox I: Practice Questions

2 multiple-choice questions marked as you go, and 4 written questions with worked solutions. All on Topic 3: Redox I.

6 questions19 marksFree, no account

Question 1

1 mark

In which of the following species does chlorine have an oxidation number of \(+3\)?

Question 2

1 mark

Consider the following disproportionation reaction in alkaline conditions:
\(3Cl_{2} + 6OH^{-} \rightarrow 5Cl^{-} + ClO_{3}^{-} + 3H_{2}O\)
What are the changes in the oxidation number of chlorine in this reaction?

Question 3

2 marks

State the oxidation number of sulfur in the following species:
(i) \(S_{8}\)
(ii) \(SO_{4}^{2-}\)

Write your answer out first, then check it against the worked solution.

Question 4

5 marks

Construct a balanced full ionic equation for the redox reaction between acidified potassium manganate(VII) solution and iron(II) sulfate solution, using the relevant half-equations.

Write your answer out first, then check it against the worked solution.

Question 5

5 marks

The reaction between chlorine and cold, dilute aqueous sodium hydroxide is a disproportionation reaction. Write a balanced ionic equation for this reaction and explain why it is classified as disproportionation in terms of oxidation numbers.

Write your answer out first, then check it against the worked solution.

Question 6

5 marks

Consider the reaction between bromate(V) ions and bromide ions in acidic solution:
\( BrO_{3}^{-}(aq) + 5Br^{-}(aq) + 6H^{+}(aq) \rightarrow 3Br_{2}(aq) + 3H_{2}O(l) \)

(a) State the oxidation number of bromine in \( BrO_{3}^{-} \) and in \( Br_{2} \).
(b) Write the two half-equations for this redox reaction, clearly identifying which is oxidation and which is reduction.
(c) Define the term disproportionation and explain, using oxidation numbers, why the reverse of the reaction above is a disproportionation reaction.

Write your answer out first, then check it against the worked solution.

* The content provided by thinka is generated by AI and may not always be accurate or up-to-date. Please use it as a supplementary resource and verify with official materials.

You've seen the model answer. Now get yours marked.

This page can show you how a good answer looks. It cannot tell you what your answer was missing. thinka marks your written work against the real mark scheme in about 15 seconds.

Get My Answers Marked Back to the notes

Want more questions like these? Get a fresh set on this topic, graded as you go.

Practice More