IGCSE Chemistry 0620 · Electrochemistry · 4.1

Electrolysis: past paper questions

205 real questionsasked in 9 of the last 10 exam series2019–2026usually: Name, State, Explain, Describe, Which

Real questions on electrolysis

The newest 20 of 205 written questions. Open one to see it on the real paper.

0620/31 · May/June 2026 · Q6d(i)[2]
Define the term electrolysis.
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0620/31 · May/June 2026 · Q6d(ii)[1]
Name a metal that is used as an inert electrode.
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0620/31 · May/June 2026 · Q6d(iii)[3]
Name the products formed at each electrode during the electrolysis of molten cobalt( II ) chloride, and give the observations at the positive electrode. product at the negative electrode product at the positive electrode observations at the positive electrode
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0620/32 · May/June 2026 · Q6d(i)[1]
Name a non-metal that is used as an inert electrode.
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0620/32 · May/June 2026 · Q6d(ii)[3]
Name the products formed at each electrode during the electrolysis of molten nickel( II ) bromide, and give the observations at the positive electrode. product at the negative electrode product at the positive electrode observations at the positive electrode
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0620/33 · May/June 2026 · Q6d[3]
Another compound of titanium is titanium( III ) chloride. Molten titanium( III ) chloride is electrolysed using graphite electrodes. Name the products formed at each electrode during the electrolysis of molten titanium( III ) chloride, and give the observations at the positive electrode. product at the negative electro...
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0620/41 · May/June 2026 · Q5a(i)[1]
Name the process that occurs when an aqueous ionic compound decomposes by the passage of an electric current.
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0620/41 · May/June 2026 · Q5a(ii)[2]
Give two reasons why graphite is suitable for use as an electrode.
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0620/41 · May/June 2026 · Q5a(iii)[2]
Write an ionic half-equation for the formation of hydrogen at the cathode.
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0620/41 · May/June 2026 · Q5a(iv)[2]
Explain why oxygen is produced at the anode.
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0620/41 · May/June 2026 · Q5a(v)[1]
Name the type of particle responsible for the transfer of charge in the conducting wires of the external circuit.
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0620/41 · May/June 2026 · Q5a(vi)[2]
Name the products formed at each electrode when an electric current is passed through concentrated aqueous sodium chloride. anode
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0620/41 · May/June 2026 · Q5b(iv)[2]
Explain why the carbon anodes have to be replaced.
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0620/43 · May/June 2026 · Q5a(i)[1]
Give the term used to describe any liquid that undergoes electrolysis when electricity is passed through it.
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0620/43 · May/June 2026 · Q5a(ii)[2]
State two properties of a substance that make it suitable to use as an electrode.
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0620/43 · May/June 2026 · Q5a(iii)[2]
Write an ionic half-equation for the formation of bromine at the anode.
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0620/43 · May/June 2026 · Q5a(iv)[2]
Explain why hydrogen gas is produced at the cathode.
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0620/43 · May/June 2026 · Q5a(v)[1]
Name the type of particle responsible for the transfer of charge in any liquid that undergoes electrolysis.
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0620/43 · May/June 2026 · Q5a(vi)[2]
Name the products formed when electricity is passed through molten lithium bromide. at the anode
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0620/43 · May/June 2026 · Q5c[2]
Aluminium is extracted by electrolysis using cryolite. State two reasons why cryolite is used in this electrolysis.
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What examiners said

Comprehensive responses • A few candidates were able to define the term electrolysis using the two main points in the definition. • Some candidates were able to write down one of the points in this definition. Limited responses • Many of the candidates did not use the terms ‘ionic’ and either ‘electricity’ or ‘electric current’ in their definition.
— Examiner report, February/March 2026, 0620/32 Q3(d)(i) (Cambridge)

Comprehensive responses • Most candidates did know a property of graphite in the context of using it as an electrode. Limited responses • A few candidates did not know a property in the context of using it as an electrode. ‘Inert’ or ‘conducts electricity’ were two properties.
— Examiner report, February/March 2026, 0620/32 Q3(d)(ii) (Cambridge)

Comprehensive responses • Many candidates knew a use for graphite. Limited responses • A few candidates left this response blank. Lubricant is a good use.
— Examiner report, February/March 2026, 0620/32 Q3(d)(iii) (Cambridge)

Practise this topic

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Practise electrolysis

In the syllabus

4.1 Electrolysis

Define electrolysis as the decomposition of an ionic compound, when molten or in aqueous solution, by the passage of an electric current
Identify in simple electrolytic cells: (a) the anode as the positive electrode (b) the cathode as the negative electrode (c) the electrolyte as the molten or aqueous substance that undergoes electrolysis
Identify the products formed at the electrodes and describe the observations made during the electrolysis of: (a) molten lead(II) bromide (b) concentrated aqueous sodium chloride (c) dilute sulfuric acid using inert electrodes made of platinum or carbon / graphite
State that metals or hydrogen are formed at the cathode and that non-metals (other than hydrogen) are formed at the anode
Predict the identity of the products at each electrode for the electrolysis of a binary compound in the molten state
State that metal objects are electroplated to improve their appearance and resistance to corrosion
Describe how metals are electroplated
Describe the transfer of charge during electrolysis to include: (a) the movement of electrons in the external circuit (b) the loss or gain of electrons at the electrodes (c) the movement of ions in the electrolyte
Identify the products formed at the electrodes and describe the observations made during the electrolysis of aqueous copper(II) sulfate using inert carbon / graphite electrodes and when using copper electrodes
Predict the identity of the products at each electrode for the electrolysis of a halide compound in dilute or concentrated aqueous solution
Construct ionic half-equations for reactions at the anode (to show oxidation) and at the cathode (to show reduction)

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