Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Oxidation and reduction
19 practice questions
Practice questions
11–19 of 19
Question 11
3 marks · Normal
Answer and see the solution →In a reaction, iron(III) oxide reacts with aluminium powder:
Describe, in terms of electron transfer, what happens to aluminium atoms during this reaction.
Question 12
3 marks · Normal
Answer and see the solution →Explain why magnesium acts as a reducing agent when it is heated with zinc oxide, in terms of oxygen transfer.
Question 13
4 marks · Normal
Answer and see the solution →Substances involved in a reaction. Substance Oxygen gained/lost Sulphur dioxide gains oxygen Oxygen no change Potassium chloride no change Sulphur trioxide formed from SO2 + O2 (a)[2 marks]Which substance in the table is oxidised? Explain your answer.
(b)[2 marks]Identify the oxidising agent in this process. Justify your choice.
Question 14
1 mark · Normal
Answer and check →Which equation shows reduction in terms of electron transfer?
- A.A. Cu^{2+} + 2e^- \to Cu
- B.B. Mg \to Mg^{2+} + 2e^-
- C.C. Fe \to Fe^{3+} + 3e^-
- D.D. Cl_2 + 2e^- \to 2Cl^-
Question 15
2 marks · Normal
Answer and see the solution →Complete the sentences about oxidation and reduction in terms of oxygen:
A substance is _______ if it gains oxygen, and it is _______ if it loses oxygen.
Question 16
4 marks · Normal
Answer and see the solution →Potassium chlorate(V) reacts on heating with manganese(IV) oxide catalyst:
(a)[2 marks]Identify which substance is reduced and which is oxidised in this reaction.
(b)[2 marks]Name the oxidising agent in this reaction. Explain your answer.
Question 17
2 marks · Hard
Answer and see the solution →In the reaction below, identify the oxidising agent and the reducing agent: State each answer as a chemical formula.
Question 18
5 marks · Hard
Answer and see the solution →The following ionic equation represents a reaction between zinc metal and copper(II) ions:
(a)[2 marks]State which species is oxidised and which is reduced. Give your answers as chemical symbols or formulae.
(b)[1 mark]Write a half-equation for the oxidation process.
(c)[2 marks]Explain, in terms of electron transfer, why zinc is considered a reducing agent in this reaction.
Question 19
2 marks · Hard
Answer and see the solution →Describe what is meant by 'oxidation' and 'reduction', in terms of oxygen transfer.