The mole and the Avogadro constant: past paper questions
Real questions on the mole and the avogadro constant
The newest 20 of 50 written questions. Open one to see it on the real paper.
- 9701/52 · February/March 2026 · Q1d(vi)[1]
The mass of residue is 0.3579 g. Calculate the amount, in mol, of potassium ions, K + , in solid X in the small beaker in 1(a). [M r : KB(C 6 H 5 ) 4 , 357.9] amount of K + in solid X = mol
See it on the paper → - 9701/52 · February/March 2026 · Q1d(vii)[1]
Use your answer to 1(d)(vi) to determine the mass of KCl in solid X. mass of KCl in solid X = g
See it on the paper → - 9701/52 · February/March 2026 · Q1e(i)[1]
Calculate Q. Q = mol
See it on the paper → - 9701/52 · February/March 2026 · Q1e(ii)[1]
Use equation 1 to calculate the mass, in g, of NaCl in solid X. [If you were unable to obtain an answer to 1(e)(i), use Q = 0.014 mol. This is not the correct answer.] mass of NaCl in solid X = g
See it on the paper → - 9701/52 · February/March 2026 · Q1e(iii)[1]
Calculate the mass of NaNO 3 in solid X using your answers to 1(d)(vii), 1(e)(ii) and the information given. mass of NaNO 3 in solid X = g
See it on the paper → - 9701/53 · October/November 2025 · Q1a(i)[1]
Calculate the mass of solid silver nitrate, AgNO 3 (s), needed to make 250.0 cm 3 of 0.0500 mol dm –3 AgNO 3 (aq). Give your answer to two decimal places. mass of AgNO 3 (s) = g
See it on the paper → - 9701/53 · October/November 2025 · Q1d(i)[1]
Calculate the amount, in mol, of AgNO 3 (aq) in the mean titre of 20.65 cm 3 . amount of AgNO 3 = mol
See it on the paper → - 9701/53 · October/November 2025 · Q1d(ii)[1]
Calculate the amount, in mol, of BaCl 2 (aq) in 250 cm 3 of solution A. amount of BaCl 2 = mol
See it on the paper → - 9701/53 · May/June 2025 · Q1i(i)[2]
[M r : C 6 H 5 CH(OH)CH 3 , 122.0] percentage yield of C 6 H 5 CH(OH)CH 3 = % At the end of step 8, 2.17 g of 1-phenylethanol is obtained. Determine whether bromobenzene or ethanal is the limiting reagent and hence calculate the percentage yield of 1-phenylethanol. Show your working. (i)
See it on the paper → - 9701/41 · October/November 2024 · Q4d(ii)[2]
A 25.0 cm 3 sample of a solution of Na 2 C 2 O 4 reacts with exactly 16.20 cm 3 of an acidified solution of 0.0500 mol dm –3 K 2 Cr 2 O 7 . Calculate the concentration of the solution of Na 2 C 2 O 4 . [Na 2 C 2 O 4 ] = mol dm –3
See it on the paper → - 9701/51 · October/November 2024 · Q1e(i)[1]
Calculate the amount, in mol, of (C 6 H 2 I 2 O) 2 (s) collected in step 9. [M r : (C 6 H 2 I 2 O) 2 , 687.6] amount of (C 6 H 2 I 2 O) mol
See it on the paper → - 9701/51 · October/November 2024 · Q1e(ii)[1]
Use your answer to (i) to calculate the mass, in g, of C 9 H 8 O 4 (s) in the powdered tablets added to the flask in step 2. mass of C 9 H 8 O 4 (s) g
See it on the paper → - 9701/51 · October/November 2024 · Q2b(i)[1]
Calculate the mass of C 25 H 30 N 3 Cl (s) needed to prepare solution D. Give your answer to three significant figures. [M r : C 25 H 30 N 3 Cl (s), 407.5] mass of C 25 H 30 N 3 Cl (s) = g
See it on the paper → - 9701/53 · October/November 2024 · Q1e(i)[1]
Calculate the amount, in mol, of (C 6 H 2 I 2 O) 2 (s) collected in step 9. [M r : (C 6 H 2 I 2 O) 2 , 687.6] amount of (C 6 H 2 I 2 O) mol
See it on the paper → - 9701/42 · May/June 2024 · Q2b[3]
X is a solution of NaNO 2 . 250.0 cm 3 of X is added to 50.0 cm 3 of 0.125 mol dm –3 acidified MnO 4– (aq). The MnO 4– (aq) ions are in excess; all the NO 2– ions are oxidised in the reaction. The unreacted MnO 4– (aq) required 22.50 cm 3 of 0.0400 mol dm –3 Fe 2+ (aq) to reach the end‑point. The relevant half‑equation...
See it on the paper → - 9701/43 · May/June 2024 · Q1b[4]
Barium hydroxide, Ba(OH) 2 , is a strong base. A 250.0 cm 3 solution of Ba(OH) 2 with a pH of 12.2 is made by dissolving Ba(OH) 2 in distilled water. Calculate the mass of Ba(OH) 2 required to make this solution. Show your working. [M r : Ba(OH) 2 , 171.3] mass of Ba(OH) 2 = g
See it on the paper → - 9701/51 · May/June 2024 · Q1a(i)[1]
Determine the mass, in g, of Na 2 S 2 O 3 •5H 2 O(s) required to prepare 500.0 cm 3 of 0.00200 mol dm –3 Na 2 S 2 O 3 (aq). mass of Na 2 S 2 O 3 •5H 2 O(s) = g
See it on the paper → - 9701/51 · October/November 2023 · Q2c(iv)[3]
The student wants to perform a similar experiment using 0.200 mol dm –3 C 6 H 5 N 2 Cl (aq). Describe how the student should make a standard solution of 100.0 cm 3 of 0.200 mol dm –3 C 6 H 5 N 2 Cl (aq) starting from a solution of 0.500 mol dm –3 C 6 H 5 N 2 Cl (aq). Give the name and size of any key apparatus which sh...
See it on the paper → - 9701/51 · October/November 2023 · Q2c(v)[1]
Explain why (iv) must be carried out at a temperature below 5 °C.
See it on the paper → - 9701/52 · October/November 2023 · Q2b[3]
The student wants to perform a similar experiment using 0.100 mol dm –3 HCl (aq). Describe how the student should make a standard solution of 250.0 cm 3 of 0.100 mol dm –3 HCl (aq) starting from a solution of 2.00 mol dm –3 HCl (aq). Give the name and size of any key apparatus which should be used and describe how the...
See it on the paper →
What examiners said
Comprehensive responses • Most candidates correctly calculated the answer. Limited responses • Some candidates did not appreciate that only 25.0 cm3 of the original 250 cm3 solution were used and gave answers that were out by a factor of 10.
— Examiner report, February/March 2026, 9701/52 Q1(d)(vi) (Cambridge)
Comprehensive responses • Most candidates correctly multiplied their answer to 1(d)(vi) by the relative formula mass of KCl. Limited responses • Some candidates calculated the relative formula mass of KCl incorrectly.
— Examiner report, February/March 2026, 9701/52 Q1(d)(vii) (Cambridge)
Comprehensive responses • Most candidates calculated Q correctly although some answers were out by a factor of 10. Limited responses • Some candidates attempted to calculate n.
— Examiner report, February/March 2026, 9701/52 Q1(e)(i) (Cambridge)
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