Electrochemistry: past paper questions
Real questions on electrochemistry
The newest 20 of 414 written questions, plus 159 multiple-choice. Open one to see it on the real paper.
- 9701/41 · May/June 2026 · Q4d[2]
Identify the strongest oxidising agent and the strongest reducing agent in Table 4.1. strongest oxidising agent strongest reducing agent
See it on the paper → - 9701/41 · May/June 2026 · Q5e(iii)[1]
Name the type of reaction that occurs in both reactions 1 and 2.
See it on the paper → - 9701/41 · May/June 2026 · Q8a(vi)[1]
Suggest a reagent for step 3.
See it on the paper → - 9701/41 · May/June 2026 · Q9c(ii)[1]
W reacts under suitable conditions to form two molecules of P and one molecule of R. Name the type of reaction.
See it on the paper → - 9701/21 · October/November 2025 · Q1c(i)[1]
Identify the species that is reduced in half-equation 2. Explain your answer.
See it on the paper → - 9701/21 · October/November 2025 · Q4a(i)[1]
Identify the type of reaction that occurs in reaction 1. (a) (i)
See it on the paper → - 9701/22 · October/November 2025 · Q1c(i)[1]
Identify the species that is reduced in half-equation 2. Explain your answer.
See it on the paper → - 9701/22 · October/November 2025 · Q4c(i)[1]
State the colour change that takes place in the reaction mixture.
See it on the paper → - 9701/23 · October/November 2025 · Q1c(i)[1]
Identify the species that is reduced in half-equation 2. Explain your answer.
See it on the paper → - 9701/23 · October/November 2025 · Q1d(iii)[4]
CrO 42– (aq) ions are yellow and Cr 2 O 72– (aq) ions are orange. State what is observed when the following changes are made to an equilibrium mixture of acidified CrO 42– (aq) and Cr 2 O 72– (aq) ions. • The equilibrium mixture is warmed gently. observation explanation • Dilute HCl (aq) is added to the equilibrium mix...
See it on the paper → - 9701/23 · October/November 2025 · Q4a(i)[1]
Identify the type of reaction that occurs in reaction 1. (a) (i)
See it on the paper → - 9701/41 · October/November 2025 · Q2a[1]
Iron can form stable ions in the +2 and +3 oxidation states. Explain why transition elements have variable oxidation states.
See it on the paper → - 9701/41 · October/November 2025 · Q5f(ii)[2]
Complete the equation for the reaction between acidified VO 3– ions and Zn metal. 2+ 2+ (ii)
See it on the paper → - 9701/42 · October/November 2025 · Q5b(i)[2]
A Co 2+ /Co electrode is constructed in which [Co 2+ ] is 0.020 mol dm –3 at 298 K. Use the Nernst equation to show that the E value for this Co 2+ / Co electrode is –0.33 V.
See it on the paper → - 9701/42 · October/November 2025 · Q5b(ii)[1]
An electrochemical cell is constructed using the Co 2+ / Co electrode described in (b)(i) and a Cr 2 O 72– / Cr 3+ electrode in which all conditions are standard. Calculate the value of E cell . E cell =
See it on the paper → - 9701/42 · October/November 2025 · Q5b(iii)[1]
A current is drawn from the electrochemical cell described in (b)(ii). Write an equation for the reaction taking place in the cell.
See it on the paper → - 9701/42 · October/November 2025 · Q5b(iv)[1]
Complete the sentences to identify the negative electrode and the direction of electron flow when a current is drawn from the cell described in (b)(ii). The electrode is the negative electrode.
See it on the paper → - 9701/42 · October/November 2025 · Q5c[3]
A molten Co 2+ salt is electrolysed using a current of 0.500 A. 0.547 g of cobalt metal forms at the cathode. Under the conditions used no other reduction reaction occurs at the cathode. Calculate the time in minutes for which the current flows to produce this mass of cobalt. Give your answer to three significant figur...
See it on the paper → - 9701/43 · October/November 2025 · Q2a[1]
Iron can form stable ions in the +2 and +3 oxidation states. Explain why transition elements have variable oxidation states.
See it on the paper → - 9701/43 · October/November 2025 · Q5f(ii)[2]
Complete the equation for the reaction between acidified VO 3– ions and Zn metal. 2+ 2+ (ii)
See it on the paper →
What examiners said
There were many correct answers here. Candidates should be careful to reference the relevant active species.
— Examiner report, February/March 2025, 9701/22 Q3(b) (Cambridge)
This was answered well. Candidates were able to identify 2,4-DNPH and effervescence with Na(s) easily. Common errors were mainly to do with the observation of the reaction with acidified K2Cr2O7, answers to which incorrectly referenced precipitates or the reverse colour change.
— Examiner report, February/March 2025, 9701/22 Q4(a) (Cambridge)
The Eocell value was calculated correctly by most candidates but the equation for the overall cell reaction was often constructed incorrectly.
— Examiner report, February/March 2025, 9701/42 Q1(e)(i) (Cambridge)
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