Acid–base titrations: past paper questions
Real questions on acid–base titrations
The newest 20 of 20 written questions. Open one to see it on the real paper.
- 0971/62 · October/November 2025 · Q2a[5]
Use the burette diagrams in Fig. 2.1 and Fig. 2.2 to record the readings for Experiment 1 and Experiment 2 in Table 2.1. Complete Table 2.1. 1 1 20 20 40 40 2 2 21 21 41 41 3 3 22 22 42 42 initial burette reading initial burette reading burette reading at burette reading at first end-point first end-point burette readi...
See it on the paper → - 0971/62 · October/November 2025 · Q2b(i)[1]
Explain why the conical flask is rinsed with distilled water at the start of Experiment 2.
See it on the paper → - 0971/62 · October/November 2025 · Q2b(ii)[2]
At the start of Experiment 1, the burette is rinsed with distilled water and then with solution C. Explain how the volume added from the burette to reach the first end-point would be different if the burette was not rinsed with solution C.
See it on the paper → - 0971/62 · October/November 2025 · Q2b(iii)[1]
Explain why the conical flask is placed on a white tile during the titration.
See it on the paper → - 0971/62 · October/November 2025 · Q2c[3]
Compare the concentration of solution C used in Experiment 1 with the concentration of solution D used in Experiment 2. Explain your answer.
See it on the paper → - 0971/62 · October/November 2025 · Q2d(i)[2]
Deduce the volume of solution C required to reach the first end-point if Experiment 1 is repeated using 50 cm 3 of solution B instead of 25 cm 3 . volume of solution C =
See it on the paper → - 0971/61 · May/June 2024 · Q1c[1]
D escribe how the student can determine the volume of dilute hydrochloric acid used in this titration.
See it on the paper → - 0971/61 · May/June 2023 · Q2a[4]
Use the burette diagrams in Fig. 2.1 and Fig. 2.2 to complete Table 2.1. Experiment 1 0 17 1 18 2 19 initial reading final reading Fig. 2.1 Experiment 2 8 20 9 21 10 22 initial reading final reading Fig. 2.2 Table 2.1 Experiment 1 using solution A Experiment 2 using solution B final burette reading / cm 3 initial buret...
See it on the paper → - 0971/61 · May/June 2023 · Q2d(i)[1]
Deduce which solution of copper( II ) sulfate, A or B, is more concentrated. Explain your answer.
See it on the paper → - 0971/61 · May/June 2023 · Q2d(ii)[1]
Deduce how many times more concentrated this solution of copper( II ) sulfate is than the other solution of copper( II ) sulfate.
See it on the paper → - 0971/61 · May/June 2023 · Q2f[1]
Deduce the volume of solution A required when Experiment 1 is carried out with 10 cm 3 of aqueous ammonia.
See it on the paper → - 0971/41 · May/June 2022 · Q3c(ii)[1]
State the colour change of the methyl orange indicator in step 4. from to
See it on the paper → - 0971/62 · May/June 2022 · Q2c[1]
State the colour change observed at the end-point when dilute hydrochloric acid is added to methyl orange in an alkaline solution. from to
See it on the paper → - 0971/62 · May/June 2022 · Q2d[1]
For Experiment 1, compare the volume of dilute hydrochloric acid needed for the first colour change with the volume of dilute hydrochloric acid for the second colour change.
See it on the paper → - 0971/62 · May/June 2022 · Q2e[1]
Compare the concentration of solution K used in Experiment 1 to the concentration of solution L used in Experiment 2. Explain your answer.
See it on the paper → - 0971/62 · May/June 2022 · Q2f(ii)[1]
State why using 50 cm 3 of solution L would cause a problem.
See it on the paper → - 0971/62 · May/June 2022 · Q2g[1]
State the advantage of using a pipette instead of the measuring cylinder in these experiments.
See it on the paper → - 0971/41 · May/June 2020 · Q4d(i)[1]
Name a suitable indicator to use in this titration.
See it on the paper → - 0971/41 · May/June 2020 · Q4d(ii)[3]
Calculate the concentration of the H 2 SO 4 (aq) in mol / dm 3 using the following steps. ● ● Calculate the number of moles of NaOH in 25.0 cm 3 . moles = ● ● Deduce the number of moles of H 2 SO 4 that reacted with the 25.0 cm 3 of NaOH(aq). moles = ● ● Calculate the concentration of H 2 SO 4 (aq) in mol / dm 3 . conc...
See it on the paper → - 0971/61 · May/June 2020 · Q2e[2]
What volume of dilute hydrochloric acid would be required if Experiment 3 was repeated using thymolphthalein indicator instead of methyl orange indicator? volume =
See it on the paper →
What examiners said
Candidates performed well on this question. Most candidates were able to read the burette scales and calculate the volumes added. Many gave all burette readings to a consistent number of decimal places. However, some candidates recorded the initial reading in Experiment 2 as 21 rather than 21.0. Some candidates gave readings to a consistent number of significant figures, rather than decimal places...
— Examiner report, May/June 2023, 0971/61 Q2(a) (Cambridge)
Better performing candidates correctly stated that solution B was the more concentrated and correctly explained this by stating that a smaller volume of solution B than solution A reacted with the same volume of aqueous ammonia. The most common error was to state that solution A was the more concentrated because a greater volume of A was required.
— Examiner report, May/June 2023, 0971/61 Q2(d)(i) (Cambridge)
The majority of candidates correctly divided the bigger titre by the smaller to produce an answer of ×1.5. However, the most common errors were to divide the smaller titre by the larger which give and answer of <1, and so did not answer the question for how many times more concentrated the solution was, or to just subtract one titre from the other and so calculate the difference in the two titres....
— Examiner report, May/June 2023, 0971/61 Q2(d)(ii) (Cambridge)
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