Calculations from equations: Edexcel International A Level Chemistry questions

Every Edexcel International A Level Chemistry exam question on Calculations from equations (specification points 1.6–1.12), 2019–2025, with its mark scheme and examiner’s report.

All 455 questions on Calculations from equations, as a list

June 2025, AS Unit 1, Q2 (1 mark): What volume of sulfur dioxide gas reacts completely with 50 cm3 of 0.12 mol dm–3 sodium hydroxide solution? [molar volume of a gas = 24 dm3 at room temperature
June 2025, AS Unit 1, Q5 (1 mark): Which mass of fertiliser contains 467 g of nitrogen? A 2 kg sodium nitrate (NaNO3 ; Mr = 85) B 1 kg urea (NH2CONH2 ; Mr = 60) C 1 kg ammonium nitrate (NH4NO3 ;
June 2025, AS Unit 1, Q9 (1 mark): Which method for the preparation of hydrogen has the highest atom economy by mass? A 2H2O → 2H2 + O2 B CH4 + H2O → 3H2 + CO C CO + H2O → H2 + CO2 D CH3OH + H2O
June 2025, AS Unit 1, Q10 (1 mark): Which reaction to produce copper(II) nitrate (Mr = 187.5) has an atom economy of 46.5% by mass? A Cu + 4HNO3 → Cu(NO3)2 + 2NO2 + 2H2O B 2Cu + Pt(NO3)4 → 2Cu(NO3
June 2025, AS Unit 1, Q11 (1 mark): What is the maximum volume of butane which will completely burn in 130 cm3 of oxygen? C4H10 + 6.5O2 → 4CO2 + 5H2O A 10 cm3 B 15 cm3 C 20 cm3 D 40 cm3
June 2025, AS Unit 1, Q12 (1 mark): A 3.50 g sample of an organic compound will completely burn forming 5.15 g of carbon dioxide and 2.11 g of water. What is the empirical formula of the compound?
June 2025, AS Unit 1, Q20(a) (4 marks): According to data from 2021, there are 415 ppm of carbon dioxide in the atmosphere by volume. Calculate the moles of carbon dioxide present in 1.00 m3 of air at
June 2025, AS Unit 1, Q20(b)(iii) (6 marks): Kerosene is used as aeroplane fuel. A jet plane can carry a maximum of 800 passengers and uses 11 400 dm3 of fuel per hour. Calculate the mass, in kg, of carbon
June 2025, AS Unit 1, Q22(c) (3 marks): Calculate the percentage yield if 1.00 g of trichlorobutane is produced from 10.0 g butane using the overall equation shown. C4H10 + 3Cl2 → C4H7Cl3 + 3HCl (3)
June 2025, AS Unit 2, Q8 (1 mark): 20 g of an impure sample of calcium carbonate is heated and decomposes completely. 3.6 dm3 of carbon dioxide is produced at room temperature and pressure (r.t.p
June 2025, AS Unit 2, Q16(b) (2 marks): A sample of cyclohexanol contains 7.13 g of carbon, 1.19 g of hydrogen and 1.58 g of oxygen. Show that this data is consistent with the empirical formula C6H12O
June 2025, AS Unit 2, Q17(a) (7 marks): The value of n in a sample of a hydrated magnesium carbonate, MgCO3∙nH2O , can be determined by the reaction with hydrochloric acid. The equation for the reacti
June 2025, AS Unit 3, Q4(e)(i) (3 marks): Calculate the maximum mass of iron(III) chloride that could be produced. (3)
June 2025, AS Unit 3, Q4(e)(ii) (2 marks): Explain why, during an experiment using 2.00 g of accurately weighed out iron wool, the mass of product measured in the weighing bottle was greater than your an
June 2025, AS Unit 3, Q5(a) (2 marks): Show, by calculation, that magnesium was in excess. (2)
June 2025, Unit 5, Q11(d) (1 mark): What is the percentage of carbon, by mass, in the final product? (1) [Mr of the final product = 165] A 58.2% B 65.5% C 72.7% D 80.0%
June 2025, Unit 5, Q12 (1 mark): A substituted benzene compound has the general formula CnH2n−6 . When completely combusted, 0.025 mol of the compound produced 11.0 g of CO2 . Which could be th
June 2025, Unit 5, Q17(b) (2 marks): When trimethylamine oxidises, it forms trimethylamine N-oxide, C3H9NO. −6 mol dm −3 Healthy humans have a concentration of 3.90 × 10 trimethylamine N-oxide in t
June 2025, Unit 5, Q18(d)(ii) (3 marks): The yield, by mass, for the formation of sunset yellow is 67.9%. Calculate the mass of sunset yellow produced from 5.00 g of compound A. [Mr of sunset yellow =
June 2025, Unit 5, Q20(e) (2 marks): 5-Nitrosalicylic acid has a solubility of 1 g in 1475 cm –3. Calculate the concentration of a saturated solution in mol dm (2) [5-nitrosalicylic acid Mr = 183]
June 2025, Unit 6, Q1(a)(iv) (2 marks): Give the formula of salt A, which has a molar mass of 197.9 g mol–1. (2)
June 2025, Unit 6, Q2(c)(ii) (4 marks): The equation for the titration is shown. Ca(OH)2(aq) + 2HCl(aq) → CaCl2(aq) + 2H2O(l) A data book value for the concentration of a saturated solution of calcium
June 2025, Unit 6, Q4(c) (4 marks): Deduce why the volume of benzoyl chloride added in Step 2 does not need to be exact. Include a calculation in your answer. [Density of benzoyl chloride = 1.21 g
June 2025, Unit 6, Q4(g) (2 marks): Calculate the mass of phenyl benzoate that can be prepared from 5.00 g of phenol if the overall yield, by mass, is 65.0%. (2)
June 2025 (A), Unit 5, Q15(b) (1 mark): What mass of aspirin would be produced from 47.0 g of phenol in this reaction scheme? [Data: Mr phenol = 94 Mr aspirin = 180] (1) A 47.3 g B 65.3 g C 90.0 g D 9
June 2025 (A), Unit 5, Q19(b)(ii) (3 marks): Determine the molecular formula of E, using the data shown and the information in (b). (3) % carbon % hydrogen % nitrogen % oxygen 51.1 8.51 15.1
January 2025, AS Unit 1, Q2 (1 mark): How many moles of ions are there in 40 cm3 of a solution of 0.050 mol dm–3 magnesium nitrate, Mg(NO3)2? A 0.0020 mol B 0.0040 mol C 0.0060 mol D 0.0080 mol
January 2025, AS Unit 1, Q4 (1 mark): NxO4 is an oxide of nitrogen. The percentage by mass of oxygen in this oxide is 69.57%. What is the relative molecular mass of this oxide? A 78 B 92 C 106 D 109
January 2025, AS Unit 1, Q5 (1 mark): Four different solutions contain chloride ions. Three of the solutions contain the same number of moles of chloride ions. Which solution contains a different nu
January 2025, AS Unit 1, Q6 (1 mark): A solution contains 95 ppm of a solute. What mass of the solute is dissolved in 1 kg of this solution? A 95 g B 0.95 g C 0.095 g D 0.000095 g
January 2025, AS Unit 1, Q7 (1 mark): A sample of hydrated magnesium sulfate contains 43% by mass of water. What is the formula of this magnesium sulfate? A MgSO4•9H2O B MgSO4•5H2O C MgSO4•2.5H2O D
January 2025, AS Unit 1, Q8 (1 mark): Ethanoic acid can be produced by the oxidation of butane. 2C4H10 + 5O2 → 4CH3COOH + 2H2O The atom economy, by mass, for the production of ethanoic acid is A 13%
January 2025, AS Unit 1, Q24(a)(i) (4 marks): Calculate the number of moles of X in the sample. [R = 8.31 J mol–1 K–1] Use pV = nRT (4)
January 2025, AS Unit 1, Q24(a)(ii) (1 mark): Deduce the relative molecular mass of X. (1)
January 2025, AS Unit 1, Q24(a)(iii) (2 marks): Compound X contains 85.7 % carbon and 14.3 % hydrogen by mass. Calculate the empirical formula of X. (2)
January 2025, AS Unit 1, Q24(a)(iv) (1 mark): Deduce the molecular formula of X. (1)
January 2025, AS Unit 2, Q3 (1 mark): 20 cm3 of a saturated solution of barium nitrate at 80 °C was cooled to 20 °C. 9.32 g of crystals were precipitated. The solubility of barium nitrate is 3.74 g
January 2025, AS Unit 2, Q12(a) (1 mark): What is the concentration of the sodium hydroxide solution? (1) A 0.176 mol dm–3 B 0.239 mol dm–3 C 0.351 mol dm–3 D 0.702 mol dm–3
January 2025, AS Unit 2, Q12(b) (1 mark): What is the percentage error in the titre? [The burette is accurate to 0.05 cm3 per reading] (1) A 0.10% B 0.34% C 0.40% D 0.68%
January 2025, AS Unit 2, Q13 (1 mark): Calcium carbonate can be heated to produce calcium oxide. CaCO3 → CaO + CO2 What is the atom economy, by mass, for the formation of calcium oxide? A 44.0% B 56.
January 2025, AS Unit 2, Q14 (1 mark): What is the concentration, in mol dm–3 , when 64.5 g of sodium nitrate is dissolved in water to form 750 cm3 of solution? [Mr NaNO3 = 85.0] A 0.086 B 0.113 C 0.
January 2025, AS Unit 2, Q15 (1 mark): A volume of 10.0 cm3 of magnesium chloride solution was added to an excess of sodium hydroxide solution, forming a precipitate of magnesium hydroxide. After fil
January 2025, AS Unit 2, Q16(a) (1 mark): What is the maximum volume of gas formed at 600 K and 101 000 Pa? [ pV = nRT R = 8.31 J mol–1 K–1 ] (1) A 0.025 m3 B 0.099 m3 C 0.123 m3 D 0.247 m3
January 2025, AS Unit 2, Q16(b) (1 mark): What is the percentage yield if 25.0 g of magnesium oxide is produced? [ Mr MgO = 40.3 ] (1) A 13.6 % B 16.9 % C 31.0 % D 62.0 %
January 2025, AS Unit 2, Q21(e)(i) (2 marks): Suggest two possible advantages, other than increasing the yield, of a one‑step synthesis reaction. (2)
January 2025, AS Unit 3, Q2(a) (3 marks): Explain why the volume of hydrochloric acid added to the burette in Step 2 does not need to be exact. You must include a calculation. (3)
January 2025, AS Unit 3, Q2(b) (1 mark): State why the magnesium does not start reacting as soon as the burette is inverted in Step 4. (1)
January 2025, AS Unit 3, Q2(d) (2 marks): Calculate the volume of 1 mol of hydrogen gas at r.t.p., in cm3, using your answer to (c), the reaction equation and the mass of magnesium (0.030 g) used in the
January 2025, AS Unit 3, Q2(e) (2 marks): The magnesium ribbon used in Step 1 contained a magnesium oxide impurity of up to 2% by mass. Explain whether this magnesium oxide impurity could account for an
January 2025, AS Unit 3, Q3(a) (1 mark): State what is meant by the term standard solution. (1)
January 2025, AS Unit 3, Q3(b) (6 marks): Describe the preparation of 100.0 cm3 of a 0.0500 mol dm–3 standard solution of ethanedioic acid, starting with crystals of ethanedioic acid dihydrate, H2C2O4.2
January 2025, AS Unit 3, Q3(c)(ii) (2 marks): The titration was carried out with a few drops of phenolphthalein indicator in the conical flask. State the colour change observed at the end‑point of the titra
January 2025, AS Unit 3, Q3(c)(iv) (3 marks): The titration was repeated, giving a mean titre of 31.55 cm3. Calculate the concentration of the barium hydroxide solution, Ba(OH)2(aq), in g dm–3. Ba(OH)2 and
January 2025, AS Unit 3, Q4(f) (4 marks): Calculate the mass of 2‑chloro‑2‑methylpropane produced in this procedure, if the percentage yield is 70%. [Density of 2‑methylpropan‑2‑ol = 0.78 g cm–3] [Mr of
January 2025, Unit 4, Q20(a) (2 marks): Calculate the atom economy, by mass, for the formation of oxalic acid from the hydrolysis of 2‑oxobutanedioic acid. (2)
January 2025, Unit 4, Q20(e)(ii) (3 marks): A 0.558 mol dm−3 solution of oxalic acid is used for cleaning. Calculate the mass of spinach required to make 500 cm3 of this oxalic acid cleaning solution. [Da
January 2025, Unit 5, Q12 (1 mark): An 8.4 g sample of a hydrocarbon formed 26.4 g of carbon dioxide on complete combustion. What is the molecular formula of this compound? A CH2 B C6H6 C C2H6 D C
January 2025, Unit 5, Q13 (1 mark): What are the volumes of oxygen required and carbon dioxide produced, at room temperature and pressure (r.t.p.), on complete combustion of 5.8 g of butane, C4H10
January 2025, Unit 5, Q20(b)(ii) (4 marks): The double salt also exists as hydrated crystals. When a sample of the hydrated double salt is heated until all the water of crystallisation is removed, 56.74 %
January 2025, Unit 5, Q20(c)(i) (2 marks): Show, by calculation, that the Cr3+ level in this blood sample exceeds the safe limit. [1 billion = 1 × 109 Assume the density of blood is 1.0 g cm–3] (2)
January 2025, Unit 5, Q23(d) (3 marks): Nowadays, procaine has been replaced by lidocaine, a related compound, as a local anaesthetic in dentistry. Lidocaine is supplied in 2.2 cm3 cartridges that con
January 2025, Unit 6, Q3(b) (4 marks): Complete combustion of 4.70 g of X produces 13.80 g of carbon dioxide and 2.82 g of water. Determine the empirical formula of X. (4)
October 2024, AS Unit 1, Q4 (1 mark): Two identical sealed flasks, containing different gases, are side by side. Each flask contains one gas, with the gases at the same temperature and pressure. Fla
October 2024, AS Unit 1, Q6 (1 mark): Copper metal can displace silver from silver nitrate solution according to the equation shown. Cu + 2AgNO3 → 2Ag + Cu(NO3)2 10 g of copper metal was added to an
October 2024, AS Unit 1, Q7 (1 mark): This question is about the thermal decomposition of calcium nitrate. 2Ca(NO3)2 → 2CaO + 4NO2 + O2 What volume of gas is produced by the complete decomposition o
October 2024, AS Unit 1, Q8 (1 mark): Ethanol is formed from glucose during fermentation. C6H12O6 → 2C2H5OH + 2CO2 What is the atom economy by mass for the formation of ethanol in this reaction? A 2
October 2024, AS Unit 1, Q15(c) (1 mark): Cyclohexanol can be converted into cyclohexene. OH + H2O What mass of cyclohexanol is needed to make 7.20 g of cyclohexene, if the yield of this reaction is 72.
October 2024, AS Unit 1, Q17(a)(i) (3 marks): Complete a graph of the results by • plotting the points • labelling the axes • including a straight line of best fit. (3) 8 7 6 5 4 3 2 1 0 0 1 2 3 4 5 6 7 8
October 2024, AS Unit 1, Q17(a)(ii) (1 mark): Use your graph to determine the mass of NaOH•xH2O needed to form 4.0 g of NaOH. You must show your working on the graph. (1)
October 2024, AS Unit 1, Q17(a)(iii) (3 marks): Calculate the value of x in NaOH•xH2O using your answer to (a)(ii) and the equation for the reaction. NaOH•xH2O → NaOH + xH2O (3)
October 2024, AS Unit 1, Q17(b) (2 marks): Sodium hydroxide also forms a heptahydrate, NaOH•7H2O. Calculate the mass of this heptahydrate needed to make 250 cm3 of a solution of sodium hydroxide of conce
October 2024, AS Unit 1, Q18(d)(iii) (3 marks): One of the chlorinated compounds contains 44.1% carbon and 6.9% hydrogen by mass. Calculate the molecular formula of this compound. (3)
October 2024, AS Unit 1, Q21(b)(i) (3 marks): A sample of 5.00 g of aluminium chloride was heated to 455 K at a pressure of 1.01 × 105 Pa. When all the aluminium chloride had vaporised, the final volume of
October 2024, AS Unit 2, Q7 (1 mark): Sulfuric acid and sodium hydroxide react as shown. H2SO4(aq) + 2NaOH(aq) → Na2SO4(aq) + 2H2O(l) Which sample of sulfuric acid solution will be exactly neutralis
October 2024, AS Unit 2, Q16(a)(i) (1 mark): State how you could ensure that all the water had been removed from the crystals. (1)
October 2024, AS Unit 2, Q16(a)(ii) (3 marks): Calculate the number of water molecules of crystallisation, x, in the formula of this sample of hydrated magnesium sulfate. (3)
October 2024, AS Unit 2, Q18(a) (5 marks): Calculate the relative molecular mass of liquid X. pV = nRT Gas constant R = 8.31 J K–1 mol–1 (5)
October 2024, AS Unit 2, Q18(b) (1 mark): Each molecule of X contains carbon atoms, hydrogen atoms, and one atom of oxygen. Identify X, by name or formula, using your answer from (a). (1)
October 2024, AS Unit 2, Q20(d)(i) (3 marks): Calculate the molar ratio of Al : Li in this alloy. (3)
October 2024, Unit 4, Q20(e)(i) (2 marks): Show that the hydrochloric acid is in excess in this reaction. (2)
October 2024, Unit 4, Q20(e)(ii) (3 marks): All of the barium carbonate reacted and produced 6.19 g of hydrated barium chloride. Calculate the relative formula mass of BaCl2 • nH2O and hence deduce the va
October 2024, Unit 5, Q3 (1 mark): The formula of a chromium compound is [Cr(H2O)4Cl2]+Cl– . The molar mass of the compound is 230.5 g mol−1. What is the percentage by mass of chlorine in the com
October 2024, Unit 5, Q6(a) (1 mark): In an experiment, a 2.00 g sample of naphthalene was nitrated and produced 2.57 g of 1-nitronaphthalene. What is the percentage yield of 1-nitronaphthalene? (1)
October 2024, Unit 5, Q6(b) (1 mark): A student carrying out this experiment calculated the percentage yield of the reaction to be greater than 100%. What is the most likely explanation for this res
October 2024, Unit 5, Q9 (1 mark): The cumene process is the main industrial method for making phenol. The overall equation for this process is shown. OH O + + O O + What is the atom economy by m
October 2024, Unit 5, Q18(b)(ii) (3 marks): 12.8 cm3 of 0.05 mol dm−3 iron(III) chloride solution reacted with 8.0 cm3 of 0.08 mol dm−3 ammonium thiocyanate to form a complex ion. Deduce the formula of th
October 2024, Unit 5, Q19(a) (1 mark): Give the empirical formula of the raspberry ketone. (1)
June 2024, AS Unit 1, Q2 (1 mark): What is the maximum volume of butane that can be completely burned in 39 cm3 of oxygen at room temperature and pressure? C4H10(g) + 6.5O2(g) → 4CO2(g) + 5H2O(l)
June 2024, AS Unit 1, Q5(a) (1 mark): What is the percentage atom economy by mass for the production by fermentation? C6H12O6 → 2CH3CH2OH + 2CO2 (1) A 24.4% B 25.6% C 48.9% D 51.1%
June 2024, AS Unit 1, Q5(b) (1 mark): What is the percentage atom economy by mass for the production by hydration? C2H4 + H2O → CH3CH2OH (1) A 39.1% B 60.9% C 78.2% D 100% Use this space for any rou
June 2024, AS Unit 1, Q18(b)(i) (2 marks): The acidic derivative of tartaric acid contains 20.8% potassium, 25.5% carbon, 2.66% hydrogen by mass and the rest is oxygen. Calculate the empirical formula. (
June 2024, AS Unit 1, Q18(b)(iii) (5 marks): Calculate the maximum volume, in cm3, of carbon dioxide gas released by the neutralisation reaction in (b)(ii) from 5.00 g of baking powder, in an oven at 190°C
June 2024, AS Unit 1, Q18(b)(iv) (2 marks): Calculate the decrease in volume when the carbon dioxide gas is cooled to 20°C. (2)
June 2024, AS Unit 2, Q9 (1 mark): Which compound needs exactly nine moles of oxygen (O2) for complete combustion of one mole of the compound? A C5H12 B C6H12O C C6H14 D C6H14O
June 2024, AS Unit 2, Q11(a) (1 mark): The titration is carried out using methyl orange as an indicator. What would be the colour change at the end‑point of the titration? (1) A orange to red B red t
June 2024, AS Unit 2, Q11(b) (1 mark): What is the concentration, in mol dm–3, of the potassium sulfate solution produced by this reaction at the end‑point, to 2 significant figures? (1) A 0.010 B 0.
June 2024, AS Unit 2, Q11(c) (1 mark): Information about the uncertainties in each reading used to measure the volumes of the solutions in this titration is shown. Uncertainty / cm3 Solution Equipmen
June 2024, AS Unit 2, Q18(b)(iv) (4 marks): Compound A has Mr = 84.5, and a composition by mass of H = 1.18 %, Cl = 42.01 % and the remainder is oxygen. Deduce the molecular formula of compound A, showing
June 2024, AS Unit 2, Q20(b)(iii) (4 marks): 5 g samples of myrcene and limonene were completely hydrogenated. Calculate the volume of hydrogen required to hydrogenate each sample. Include the unit with yo
June 2024, AS Unit 3, Q1(a) (3 marks): A student used the apparatus shown to collect the gas produced from the reaction between copper(II) carbonate and sulfuric acid. inverted 250 cm3 measuring cyli
June 2024, AS Unit 3, Q1(b)(i) (1 mark): State the observation if a small volume of sodium hydrogencarbonate solution was added to show that the acid was in excess. (1)
June 2024, AS Unit 3, Q1(b)(ii) (2 marks): Describe a different test, and the positive observation, that could be carried out to show that the acid was in excess. (2)
June 2024, AS Unit 3, Q1(c)(ii) (3 marks): The reaction of 0.320 g of the Group 2 metal carbonate resulted in 89.0 cm3 of carbon dioxide gas being collected in the gas syringe. MCO3(s) + 2HCl(aq) → MCl2(
June 2024, Unit 5, Q9(a) (1 mark): What is the percentage atom economy (by mass) for the formation of 2,4,6‑tribromophenol? (1) A 42.3% B 57.7% C 69.0% D 100%
June 2024, Unit 5, Q9(b) (1 mark): When 5.00 g of phenol was reacted and purified, the percentage yield of 2,4,6‑tribromophenol was 76.8%. What mass of purified 2,4,6‑tribromophenol was formed? (
June 2024, Unit 5, Q13(b) (1 mark): If 64.3 g of the amide is produced, what volume of HCl is formed at room temperature and pressure (r.t.p.)? Assume the stoichiometry is 1 : 1. 1 mole of gas occ
June 2024, Unit 5, Q16(b)(iii) (3 marks): When a 5 dm3 sample of wastewater was treated with excess acidified sodium dimethyldithiocarbamate, 245.0 mg of the dry precipitate H+[Ni((CH3)2NCS2)3]− was for
June 2024, Unit 5, Q19(c)(iii) (4 marks): Glycerol is added to the polymer at 0.110%, by volume. Calculate the number of moles of glycerol added to 1 tonne of poly(ethenol). Data: 1 tonne = 1000 kg dens
June 2024, Unit 5, Q19(d) (5 marks): Poly(ethenol) is made from a polymer intermediate, rather than by polymerisation, as ethenol is unstable. The polymer intermediate is prepared from a monomer, X
June 2024, Unit 6, Q4(a) (3 marks): Show, by calculation, that the methanol is in excess in this preparation. [Mr values: salicylic acid = 138.0 methanol = 32.0, Density of methanol = 0.791 g cm–3
June 2024, Unit 6, Q4(e) (3 marks): The mass of pure methyl salicylate obtained was 14.1 g. Calculate the percentage yield, giving your answer to an appropriate number of significant figures. (3)
June 2024, Unit 6, Q5(b)(i) (4 marks): Calculate the molar mass of NH4X. Use the data from Steps 1 and 2. (4)
June 2024 (R), AS Unit 2, Q18(a) (3 marks): A sample of magnesium carbonate was heated for 4 minutes. The mass of the sample decreased from 4.17 g to 2.35 g. Calculate the percentage of magnesium carbonat
June 2024 (R), AS Unit 2, Q19(c) (2 marks): Ozone can also be used in the treatment of water in swimming pools. A swimming pool has a volume of 375 000 dm3 and contains 15 g of ozone. Calculate the concen
June 2024 (R), AS Unit 2, Q20(a)(i) (3 marks): Calculate the empirical formula of acetoin. You must show all your working. (3)
June 2024 (R), AS Unit 2, Q20(a)(ii) (1 mark): The molar mass of acetoin is 88.0 g mol–1. Use this information to calculate the molecular formula of acetoin. (1)
June 2024 (R), AS Unit 2, Q22(a) (3 marks): Evaluate which of these two methods used to obtain hydrogen is more sustainable. (3)
June 2024 (R), AS Unit 2, Q22(b)(i) (1 mark): Complete the table by calculating the percentage by mass of nitrogen in ammonium nitrate. (1)
June 2024 (R), AS Unit 2, Q22(b)(ii) (2 marks): Give one advantage and one disadvantage of applying ammonia directly into the soil as a fertiliser. Use information in the table and your knowledge of ammonia.
June 2024 (R), AS Unit 2, Q22(f) (4 marks): A field needs 160 kg of N per hectare to be applied using urea fertiliser. The field size is 500 m × 640 m. [1 hectare (ha) = 10 000 m2 , molar mass of urea = 6
June 2024 (R), AS Unit 3, Q1(b) (2 marks): Calculate the number of moles of sodium sulfite in 0.200 g. (2)
June 2024 (R), AS Unit 3, Q1(c) (2 marks): The reaction produced 29.5 cm3 of sulfur dioxide. Calculate the molar volume of sulfur dioxide, in dm3, from this result. (2)
June 2024 (R), AS Unit 3, Q1(d)(i) (1 mark): Calculate the minimum volume of 0.150 mol dm–3 acid that should be present in the boiling tube to fully react with 0.200 g of sodium sulfite. Use your answer to
June 2024 (R), AS Unit 3, Q1(d)(ii) (1 mark): Suggest another reason for the molar volume being lower than expected. (1)
June 2024 (R), AS Unit 3, Q3(a) (2 marks): Phenolphthalein indicator was used in the experiment. State the colour change seen at the end-point. (2)
June 2024 (R), AS Unit 3, Q3(b) (1 mark): Calculate the mean titre of sodium hydroxide solution using the concordant results. (1)
June 2024 (R), AS Unit 3, Q3(c) (2 marks): Calculate the concentration of the maleic acid solution in mol dm–3. [Mr maleic acid = 116] (2)
June 2024 (R), AS Unit 3, Q3(d) (3 marks): Use your answers to (b) and (c) to calculate the concentration of the sodium hydroxide solution in mol dm–3. (3)
January 2024, AS Unit 1, Q6 (1 mark): Which oxide of nitrogen contains 30% nitrogen by mass? [Ar values: N = 14.0 O = 16.0] A NO B NO2 C N2O D N2O3
January 2024, AS Unit 1, Q7 (1 mark): Calculate the mass of sodium carbonate (Na2CO3) required to make up 250 cm3 of a 0.100 mol dm−3 solution. [Ar values: C = 12.0 O = 16.0 Na = 23.0] A 1.30 g B 2.
January 2024, AS Unit 1, Q10 (1 mark): An excess of sodium sulfate solution is added to 50 cm3 of a 0.100 mol dm−3 solution of barium chloride. What is the mass of barium sulfate formed? [Mr value: B
January 2024, AS Unit 1, Q20(e)(i) (1 mark): Calculate the number of moles of sulfuric acid used in this experiment. (1)
January 2024, AS Unit 1, Q20(e)(ii) (1 mark): Calculate the mass of magnesium needed to react with the sulfuric acid. (1)
January 2024, AS Unit 1, Q20(e)(iii) (1 mark): Give a reason why slightly more than this mass of magnesium was used. (1)
January 2024, AS Unit 1, Q20(e)(v) (2 marks): The magnesium sulfate solution was allowed to crystallise. The crystals were dried and weighed. The mass of the hydrated crystals, MgSO4·7H2O, was 2.78 g. Calcu
January 2024, AS Unit 1, Q21(a) (4 marks): Boric acid contains 17.48% by mass of boron, 77.67% of oxygen and the remainder is hydrogen. The molar mass of boric acid is 61.8 g mol–1. [Ar values: H = 1 B =
January 2024, AS Unit 1, Q22(a) (5 marks): Calculate the molar mass of the unknown gas. (5)
January 2024, AS Unit 2, Q8 (1 mark): Equal volumes of some 0.01 mol dm–3 solutions were mixed. Which pair of solutions gave the greatest mass of precipitate? A BaCl2 and AgNO3 B BaCl2 and Ag2SO4 C
January 2024, AS Unit 2, Q10 (1 mark): Bromine, Br2(l), can be disposed of safely by reaction with aqueous sodium thiosulfate, Na2S2O3(aq). Br2(l) + 2Na2S2O3(aq) → 2NaBr(aq) + Na2S4O6(aq) What is the
January 2024, AS Unit 2, Q11 (1 mark): What is the mass of nitrogen atoms in 50 cm3 of a 2.0 mol dm–3 solution of ammonium nitrate, NH4NO3(aq)? A 35 g B 8.0 g C 2.8 g D 1.4 g
January 2024, AS Unit 2, Q24(c) (2 marks): The structure of a fire retardant is shown. Br Br Br Br Br Br Calculate the percentage by mass of bromine in this fire retardant. Give your answer to an appropr
January 2024, AS Unit 3, Q2(a) (1 mark): Draw a circle around the concordant results in the table. (1)
January 2024, AS Unit 3, Q2(b) (1 mark): Calculate the mean titre, using your answer from (a). (1)
January 2024, AS Unit 3, Q2(c)(i) (1 mark): State the colour change that occurs at the end‑point of the titration. (1)
January 2024, AS Unit 3, Q2(c)(ii) (5 marks): Calculate the percentage by mass of citric acid in the lemon juice, using your mean titre from (b). Give your answer to two significant figures. [Concentration
January 2024, AS Unit 3, Q2(d) (1 mark): Suggest a possible reason why the value obtained in (c) is valid, even though lemon juice also contains some ascorbic acid and malic acid. (1)
January 2024, AS Unit 3, Q2(e)(ii) (2 marks): Student C used sodium hydroxide solution labelled 0.103 mol dm–3 that had been made up several months ago and stored since then. Explain what effect this would
January 2024, AS Unit 3, Q3(b) (2 marks): ‘20 volume’ hydrogen peroxide solution means that 1 dm3 of the solution produces 20 dm3 of oxygen gas when it decomposes completely. 2H2O2(aq) → 2H2O(l) + O2(g)
January 2024, Unit 5, Q1(b) (1 mark): A student wishes to measure the standard cell potential, Ecell , of this cell. The right‑hand cell requires Cr3+ and Cr2+ ions. What mass of Cr2(SO4)3·18H2O mus
January 2024, Unit 5, Q14(d) (4 marks): The overall yield for the synthesis of N‑phenylethanamide from benzene was found to be 35.2%. Calculate the minimum volume of benzene, in cm3, required to make
January 2024, Unit 5, Q17(c)(i) (3 marks): Calculate the values x, y and z in Reinecke’s salt. You must show your working. (3)
January 2024, Unit 6, Q4(b) (3 marks): Show, by calculation, that ethanoic anhydride is in excess in this preparation. (3)
October 2023, AS Unit 1, Q3(b) (1 mark): Excess calcium carbide and 10 g of water react to form the hydrocarbon ethyne, C2H2. CaC2 + 2H2O → C2H2 + Ca(OH)2 What is the mass of ethyne that forms, assumin
October 2023, AS Unit 1, Q12(a) (1 mark): A sample of a gaseous mixture contains 2.19 % carbon dioxide by mass. What is the concentration of carbon dioxide in parts per million (ppm) by mass in this sam
October 2023, AS Unit 1, Q12(b) (1 mark): A solution of lead nitrate has a concentration of 15 ppm by mass. What is the mass of lead nitrate in 400 g of this solution? (1) A 6.00 × 10–3 g B 6.00 × 10–6
October 2023, AS Unit 1, Q13 (1 mark): Which solution contains chloride ions with a concentration of 0.0500 mol dm–3? [Ar values: Ca = 40.1 Cl = 35.5 Na = 23.0] Volume of solution / cm3 Solute Mass o
October 2023, AS Unit 1, Q19(a)(ii) (1 mark): The density of the E10 fuel is 0.729 g cm–3. Calculate the mass of 1500 cm3 of the fuel. (1)
October 2023, AS Unit 1, Q20(c)(i) (1 mark): Calculate the amount, in mol, of α-bisabolene in 5.51 g. (1)
October 2023, AS Unit 1, Q20(c)(ii) (3 marks): Calculate the amount, in mol, of hydrogen gas that reacted with α-bisabolene. Use the ideal gas equation, pV = nRT. [R = 8.31 J mol–1 K–1] (3)
October 2023, AS Unit 1, Q20(d)(ii) (2 marks): A sample of polyisoprene has a relative molecular mass of 50 250. Calculate the number of repeat units in the sample. (2)
October 2023, AS Unit 1, Q21(a)(ii) (2 marks): Calculate the atom economy by mass for the formation of basic nickel(II) carbonate by the reaction shown. (2)
October 2023, AS Unit 1, Q21(c)(i) (4 marks): Calculate the relative formula mass of XSO4 , using these data. (4)
October 2023, AS Unit 1, Q21(c)(ii) (1 mark): Deduce the identity of X, using your answer to (c)(i). (1)
October 2023, AS Unit 2, Q10 (1 mark): In a neutralisation reaction, 20.0 cm3 of 0.500 mol dm–3 nitric acid reacts with 10.0 cm3 of 1.00 mol dm–3 aqueous sodium hydroxide. HNO3(aq) + NaOH(aq) → NaNO3
October 2023, AS Unit 2, Q16 (1 mark): A sample of propane‑1,2‑diol with a mass of 1.52 g reacts completely with excess phosphorus(V) chloride. What is the maximum mass, in grams, of the organic prod
October 2023, AS Unit 2, Q19(a)(ii) (3 marks): Calculate the percentage by mass of potassium iodide in the mixture. Give your answer to an appropriate number of significant figures. [Ar values: Ag = 107.9 K
October 2023, AS Unit 2, Q20(b)(i) (4 marks): Calculate the concentration of the saturated solution, in g dm–3. (4)
October 2023, AS Unit 2, Q21(a)(i) (3 marks): Use these data to calculate the empirical formula of X. (3)
October 2023, AS Unit 2, Q21(a)(ii) (2 marks): The mass spectrum of X is shown. 100 80 60 Percentage relative 40 abundance 20 0.0 30 40 50 60 70 80 90 m / z Deduce the molecular formula of X, using the mass
October 2023, AS Unit 3, Q2(a) (3 marks): Draw a diagram of the apparatus used to carry out the reaction and collect the carbon dioxide produced over water in a 100 cm3 measuring cylinder. Do not show s
October 2023, AS Unit 3, Q2(d)(i) (3 marks): Plot the data on the grid. (3) 0 0
October 2023, AS Unit 3, Q2(d)(ii) (2 marks): Use the graph to determine the volume of carbon dioxide formed when 0.25 g of calcium carbonate is used. You must show your working on the graph. (2)
October 2023, AS Unit 3, Q2(d)(iii) (3 marks): Calculate a value for the molar volume of carbon dioxide, using your volume from (d)(ii) and the equation for the reaction. (3)
October 2023, AS Unit 3, Q2(e) (2 marks): Give two reasons why the molar volume obtained by this method is lower than the Data Booklet value. Assume that the experiment is carried out correctly and that
October 2023, AS Unit 3, Q3(g) (2 marks): In this preparation, 3.96 g of cyclohexanol reacted to form 2.09 g of cyclohexene. Calculate the percentage yield, by mass, in this preparation. (2)
October 2023, AS Unit 3, Q4(a) (2 marks): State the colour change of the indicator at the end-point of the titration. (2) From to
October 2023, AS Unit 3, Q4(d) (3 marks): The mean titre from two accurate titrations was 22.65 cm3 . Calculate the concentration of the hydrochloric acid, in mol dm−3 . The equation for the reaction is
October 2023, Unit 4, Q10(b) (1 mark): Reaction 1 has a yield of 90 %. What mass of 2‑methylpropanoic acid is required to produce 6.66 g of 2‑methylpropan‑1‑ol? [Mr values 2‑methylpropanoic acid = 88
October 2023, Unit 4, Q15(b) (3 marks): Calculate the temperature, in K, of the reaction mixture at equilibrium under these conditions. Use the equation pV = nRT and the data at the start of the quest
October 2023, Unit 5, Q16 (1 mark): A 10 cm3 mixture of methane and argon is ignited. The methane requires 4 cm3 of oxygen for complete combustion. What is the volume of argon, in cm3, in the mixt
October 2023, Unit 5, Q17 (1 mark): When 10 cm3 of but-1-ene, C4H8 , is ignited with excess oxygen, there is an overall decrease in volume of x cm3 . All gas volumes are measured at room temperatu
October 2023, Unit 5, Q19(a) (2 marks): A compound of iron contains, by mass, 39.5% potassium, 28.2% iron and 32.3% oxygen. Calculate the empirical formula of this compound. (2)
October 2023, Unit 5, Q21(b)(iii) (3 marks): 2.00 g of salicylic acid produced a 74.8% yield of acetylsalicylic acid. Calculate the mass of acetylsalicylic acid formed. [Mr values: salicylic acid = 138 ace
October 2023, Unit 5, Q21(f) (6 marks): Acetylsalicylic acid in aspirin tablets is hydrolysed by excess sodium hydroxide. CH3COOC6H4COOH + 2NaOH → CH3COONa + HOC6H4COONa + H2O The unreacted sodium hyd
June 2023, AS Unit 2, Q11 (1 mark): A piece of sodium weighing 1.15 g reacts completely with distilled water and the solution formed is made up to 250.0 cm3. 2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g) W
June 2023, AS Unit 2, Q12 (1 mark): Magnesium nitrate decomposes on heating. 2Mg(NO3)2(s) → 2MgO(s) + 4NO2(g) + O2(g) A sample of magnesium nitrate decomposed completely. The total volume of gas f
June 2023, AS Unit 2, Q22(b)(ii) (4 marks): A 750 cm3 bottle of a toilet cleaner contains 85.0 g of hydrochloric acid. Calculate the maximum mass of calcium carbonate limescale that could be removed by 50
June 2023, AS Unit 2, Q22(c)(ii) (4 marks): When 5.00 cm3 of a disinfectant reacts with excess hydrogen peroxide, 113 cm3 of oxygen is produced, measured at room temperature and pressure. H2O2(aq) + NaClO
June 2023, AS Unit 2, Q22(e) (4 marks): Borax is another cleaning agent used to remove limescale. Borax is a compound of sodium, boron and oxygen. Borax crystals contain water of crystallisation. The
June 2023, AS Unit 3, Q4(a)(ii) (4 marks): Calculate the value for the molar volume of hydrogen under these conditions, using the student’s results. Give your answer to an appropriate number of significa
June 2023, AS Unit 3, Q4(b)(ii) (2 marks): Give two possible reasons why this student obtained a value below the data book value. Assume the method was followed correctly and there were no measurement er
June 2023, AS Unit 3, Q4(c)(i) (2 marks): State the colour change observed in the conical flask at
June 2023, AS Unit 3, Q4(c)(ii) (2 marks): Complete the table and use the concordant results to calculate the mean titre. (2)
June 2023, AS Unit 3, Q4(c)(iii) (4 marks): The reaction taking place in this titration is Ca(OH)2(aq) + 2HCl(aq) → CaCl2(aq) + 2H2O(l) Calculate the concentration of the calcium hydroxide solution in g d
June 2023, Unit 5, Q21(c)(ii) (3 marks): Hg(CNO)2 decomposes as shown. 3Hg(CNO)2(s) → Hg(CN)2(s) + 2Hg(s) + 2CO2(g) + 2CO(g) + 2N2(g) Calculate the total volume, in cm3, of gas produced when 1.00 g of
June 2023, Unit 6, Q4(f) (3 marks): The mass of dry methyl 3‑nitrobenzoate crystals prepared by one of the students was 3.05 g. Calculate the percentage yield by mass of methyl 3‑nitrobenzoate usi
January 2023, AS Unit 1, Q2 (1 mark): What is the concentration of hydroxide ions in a solution containing 5.00 g of Ba(OH)2 in 250 cm3? [Mr Ba(OH)2 = 171.3] A 0.0292 mol dm–3 B 0.0584 mol dm–3 C 0.
January 2023, AS Unit 1, Q3 (1 mark): A sample of 15.0 g of vanadium reacted completely with 7.07 g of oxygen. What is the formula of the oxide? [Ar values: V = 50.9 O = 16.0] A VO B V2O3 C VO2 D V2
January 2023, AS Unit 1, Q4 (1 mark): What is the pressure when 5.00 mol of nitrogen in a container with a volume of 1.50 m3 is heated to 500 K? [ pV = nRT R = 8.31 J K–1 mol–1] A 13.9 Pa B 6 290 Pa
January 2023, AS Unit 1, Q23(b)(i) (2 marks): Dry air contains 21.0 % oxygen by volume. The average human breath has a volume of 500 cm3. Calculate the volume of air, in dm3, that would have to pass over th
January 2023, AS Unit 1, Q23(c)(i) (4 marks): Calculate the volume of gas, in m3, measured at room temperature and pressure (r.t.p.) that can be obtained from a bottle containing 13.9 dm3 of liquid oxygen.
January 2023, AS Unit 1, Q23(c)(ii) (1 mark): The total mass of the bottle is 80.0 kg when it is full of oxygen. Calculate the mass of an empty bottle, using your working from (c)(i). Give your answer to an
January 2023, AS Unit 1, Q23(c)(iii) (2 marks): Explain why the container needs to have such a large mass. (2)
January 2023, AS Unit 1, Q25(c) (3 marks): Aluminium trichloride also reacts with sodium hydroxide. AlCl3(g) + 3NaOH(aq) → Al(OH)3(s) + 3NaCl(aq) Calculate the maximum mass of aluminium hydroxide precipi
January 2023, AS Unit 2, Q18(b) (2 marks): Calculate the percentage atom economy by mass for the production of Ca(ClO)2 in this reaction. (2)
January 2023, AS Unit 2, Q18(c)(i) (3 marks): Calculate the mass, in kg, of Ca(ClO)2 required to treat the water needed to completely fill this swimming pool. (3)
January 2023, AS Unit 2, Q18(c)(ii) (3 marks): Calculate the volume of Cl2, at room temperature and pressure, needed to make the mass of Ca(ClO)2 calculated in (c)(i). (3)
January 2023, AS Unit 3, Q3(a)(i) (2 marks): In Step 1, the student rinsed both the pipette and the volumetric flask with deionised water before transferring 25.0 cm3 of solution A. State the effect, if an
January 2023, AS Unit 3, Q3(a)(iv) (2 marks): State the colour change of the phenolphthalein indicator at the end‑point of the titration in Step 3. (2) From to
January 2023, AS Unit 3, Q3(a)(v) (1 mark): The results of the student’s experiment are shown. Titration Trial 1 2 3 4 Final volume / cm3 29.25 33.25 32.00 29.50 28.90 Initial volume / cm3 0.00 4.50 3.15
January 2023, AS Unit 3, Q3(a)(vi) (1 mark): Give a reason why the student did not need to carry out titrations 3 and 4. (1)
January 2023, AS Unit 3, Q3(a)(vii) (1 mark): Give a reason why solution A was diluted before titrating it with this sodium hydroxide solution. (1)
January 2023, AS Unit 3, Q3(b)(ii) (5 marks): Calculate the concentration of citric acid in solution A in g dm–3, using the equation from (b)(i) and the results from (a)(v). Give your answer to three signif
January 2023, AS Unit 3, Q3(b)(iii) (2 marks): Using the result of the experiment, the student concluded that the stated concentration of the descaler (200 g dm–3) was incorrect. State whether or not this di
January 2023, Unit 4, Q18(b)(ii) (1 mark): Lactic acid is converted into compound X which is then polymerised to form PLA. The empirical formula of X is C3H4O2 and its molar mass is 144 g mol–1. Determin
January 2023, Unit 5, Q5 (1 mark): The formula of hydrated copper(II) bromide is CuBr2·4H2O. What is the percentage, by mass, of water of crystallisation in this compound? A 6.10 % B 8.06 % C 24.
January 2023, Unit 5, Q9 (1 mark): What is the minimum volume, in cm3 , of oxygen needed for the complete combustion of a mixture of 50 cm3 of propene and 50 cm3 of but-1-ene gases? All gas volum
January 2023, Unit 5, Q10 (1 mark): A sample of air contains 405 parts per million (ppm) of carbon dioxide. What is the approximate volume, in cm3 , of carbon dioxide in 250 cm3 of this air? A 0.0
January 2023, Unit 5, Q18(c) (3 marks): Hydrated potassium vanadium(III) sulfate contains 7.9 % potassium, 10.2 % vanadium, 12.9 % sulfur, 4.8 % hydrogen and 64.2 % oxygen. Calculate the empirical for
January 2023, Unit 5, Q20(b)(ii) (2 marks): Manganese(IV) oxide catalyses the decomposition of hydrogen peroxide. 2H2O2(aq) → 2H2O(aq) + O2(g) 100 cm3 of a solution of hydrogen peroxide decomposed to prod
January 2023, Unit 5, Q20(e)(i) (3 marks): Show that the potassium manganate(VII) is in excess. [Molar masses / g mol–1: C6H5CH3 = 92 KMnO4 = 158] (3)
January 2023, Unit 6, Q4(e) (2 marks): Show by calculation that, in the preparation, 10 cm3 of ethanoyl chloride is an excess compared to 5.00 g of 2‑aminobenzoic acid. Data Molar mass / g mol–1 CH3C
January 2023, Unit 6, Q4(f) (3 marks): A student carried out the preparation using the amounts of reagents given in (e) and obtained a yield of 56.7 % of 2‑ethanoylaminobenzoic acid. Calculate the ma
October 2022, AS Unit 1, Q6(b) (1 mark): A mixture of 40 cm3 of butane and 20 cm3 of oxygen reacts in a sealed system to form carbon monoxide and hydrogen. What is the total volume of gas in the system
October 2022, AS Unit 1, Q12 (1 mark): A mass of 4.08 g of hydrated copper(II) sulfate, CuSO4∙5H2O, was dissolved in deionised water to form 250 cm3 of solution. What is the concentration of the copp
October 2022, AS Unit 1, Q13 (1 mark): A mass of 2.50 g of sodium chloride reacts with excess lead(II) nitrate solution forming lead(II) chloride with a yield of 95 %. What is the mass of lead(II) ch
October 2022, AS Unit 1, Q14(b)(ii) (2 marks): Calculate the mass of barium chloride needed to form 150 cm3 of BaCl2(aq) with a concentration of 0.200 mol dm–3. Give your answer to an appropriate number of s
October 2022, AS Unit 1, Q15(d)(i) (2 marks): Calculate the empirical formula of compound X. You must show all your working. (2)
October 2022, AS Unit 1, Q15(d)(ii) (4 marks): A sample of compound X has a mass of 0.267 g and vaporises at 85.0 °C and 104 kPa to produce a gaseous sample with a volume of 98.0 cm3. Calculate the molar mas
October 2022, AS Unit 1, Q15(d)(iii) (1 mark): Deduce the molecular formula of compound X, using your answers to (d)(i) and (d)(ii). (1)
October 2022, AS Unit 1, Q16(d)(i) (2 marks): Calculate the atom economy, by mass, for the formation of germane. Use Ar of Ge = 72.6 (2)
October 2022, AS Unit 1, Q16(d)(iv) (4 marks): Germane is toxic and the maximum permitted concentration is 0.640 mg m–3 in air. Calculate the maximum number of germane molecules permitted in a laboratory wit
October 2022, AS Unit 1, Q16(e)(i) (1 mark): Calculate the number of moles of carbon dioxide formed. (1)
October 2022, AS Unit 1, Q16(e)(ii) (1 mark): Deduce the number of moles of HX formed when GeX4 reacted with the excess water. (1)
October 2022, AS Unit 1, Q16(e)(iii) (1 mark): Deduce the number of moles of GeX4 that reacted with the excess water. (1)
October 2022, AS Unit 1, Q16(e)(iv) (2 marks): Calculate the molar mass of GeX4 and hence identify X. (2)
October 2022, AS Unit 1, Q17(e)(ii) (3 marks): Orange peel contains 1.63 % of limonene by mass. A chewing gum remover contains 30 cm3 of limonene per bottle. Calculate the mass of orange peel, in kg, needed
October 2022, AS Unit 2, Q4 (1 mark): What is the mass of carbon formed when 1.80 g of propan-1-ol, C3H7OH, undergoes incomplete combustion according to the equation shown? C3H7OH(l) + 2O2(g) → 2C(s
October 2022, AS Unit 2, Q19 (1 mark): A student carries out two sets of titrations, one using methyl orange and the other using phenolphthalein as indicators. The conical flask contains sodium hydro
October 2022, AS Unit 2, Q21(c) (2 marks): Dilute sulfuric acid is used in many laboratories. It is often supplied as concentrated sulfuric acid and then diluted. A technician makes 500 cm3 of 1.5 mol dm
October 2022, AS Unit 2, Q23(e) (5 marks): Many cyclists carry a small cylinder of carbon dioxide to inflate their inner tube if it is punctured. The carbon dioxide is stored under pressure. valve carbon
October 2022, AS Unit 3, Q2(a)(i) (1 mark): Complete the table. (1)
October 2022, AS Unit 3, Q2(a)(ii) (1 mark): Calculate the mean titre for the titration. (1)
October 2022, AS Unit 3, Q2(b)(i) (2 marks): Calculate the number of moles of sulfuric acid that reacted with the sodium hydroxide in the mean titre, using your answer from (a)(ii). (2)
October 2022, AS Unit 3, Q2(b)(ii) (1 mark): Calculate the total number of moles of sulfuric acid used at the start of the experiment. (1)
October 2022, AS Unit 3, Q2(b)(iii) (4 marks): Calculate the percentage of magnesium carbonate in the antacid tablet, using your answers to (b)(i) and (b)(ii). You must show all your working. (4) MgCO3 + H2S
October 2022, AS Unit 3, Q2(c)(i) (1 mark): Give one possible reason for carrying out a rough titration. (1)
October 2022, AS Unit 3, Q2(c)(ii) (2 marks): Phenolphthalein indicator was used in the titration. State the colour change seen at the end‑point. (2) From to
October 2022, AS Unit 3, Q3(a)(ii) (1 mark): State why the height of the precipitate becomes approximately constant. (1)
October 2022, AS Unit 3, Q3(b)(i) (2 marks): Determine the minimum volume of nitrate solution needed to react completely with 5.0 cm3 of potassium iodide solution. You must show your working on the graph.
October 2022, AS Unit 3, Q3(b)(ii) (1 mark): Calculate the number of moles of potassium iodide in each test tube. (1)
October 2022, AS Unit 3, Q3(b)(iii) (1 mark): Calculate the concentration of the metal nitrate solution in g dm−3 using the information given in the procedure. (1)
October 2022, AS Unit 3, Q3(b)(iv) (4 marks): Identify X by using your answers to (b)(i), (b)(ii) and (b)(iii) to determine the Mr of the metal nitrate. You must show all your working. (4)
October 2022, Unit 5, Q21(a)(i) (4 marks): Show by calculation that the molar mass of coniine is 127 g mol−1. (4)
October 2022, Unit 5, Q22(a) (4 marks): Viridian is a blue‑green pigment with the formula M2O3·2H2O ; M is not the symbol of the element. When a sample of viridian is heated until all the water of cry
October 2022, Unit 5, Q23(a) (4 marks): Calculate the percentage composition by mass of the elements in salicin. (4)
October 2022, Unit 6, Q1(b) (4 marks): Another cobalt salt, CoCl2.xH2O(s), decomposes when heated. CoCl2.xH2O(s) → CoCl2(s) + xH2O(g) Devise an outline procedure to determine the mass of water produc
October 2022, Unit 6, Q2(c) (5 marks): The mean titre was 12.75 cm3. Calculate the percentage by mass of ammonium sulfate, (NH4)2SO4 , in the sample of plant fertiliser. [Relative formula mass of (NH
October 2022, Unit 6, Q3(a) (2 marks): Calculate which reactant is in excess in this synthesis. Molar mass / g mol–1 Density / g cm–3 Compound ethanol 46.0 0.79 butanoic acid 88.0 0.96 (2)
June 2022, AS Unit 1, Q4 (1 mark): A solution of sodium chloride, NaCl, is prepared by dissolving 10.0 g of the solid in distilled water and making the solution up to 250.0 cm3. What is the conce
June 2022, AS Unit 1, Q5 (1 mark): Ten test tubes, each containing 1.0 cm3 of a chromium chloride solution of concentration 0.1 mol dm−3, were placed in a test tube rack. Different volumes of sil
June 2022, AS Unit 1, Q19(a)(i) (2 marks): Calculate the number of moles of iron that react. (2)
June 2022, AS Unit 1, Q19(a)(ii) (2 marks): Calculate the number of moles of iron(III) chloride that react. (2)
June 2022, AS Unit 1, Q19(a)(iii) (3 marks): Use your answers to (a)(i) and (a)(ii) to write the ionic equation for the reaction of iron with iron(III) chloride. Include state symbols. You must show your w
June 2022, AS Unit 1, Q19(b) (4 marks): The concentration of the solution obtained in (a) is increased by heating it gently to remove some of the water. The solution is allowed to cool and pale green
June 2022, AS Unit 1, Q22(d)(ii) (4 marks): 2.0 mol of zingiberene react completely with hydrogen at 150 °C and a pressure of 120 kPa. Calculate the minimum volume of hydrogen needed under these condition
June 2022, AS Unit 1, Q23(a)(iii) (3 marks): One tonne of landfill waste produces approximately 12.5 dm3 of landfill gases per day. Calculate the mass of carbon dioxide produced in a year by a typical land
June 2022, AS Unit 2, Q9(a) (1 mark): What is the colour change of the indicator at the end-point of this titration? (1) A red to orange B red to yellow C yellow to orange D yellow to red
June 2022, AS Unit 2, Q9(b) (1 mark): A student carried out the first titration and did not notice that there was an air bubble between the tap and the tip of the burette. During the titration, the
June 2022, AS Unit 2, Q9(c) (1 mark): 25.0 cm3 of 0.100 mol dm−3 aqueous sodium hydroxide required a mean titre of 18.70 cm3 of sulfuric acid. 2NaOH(aq) + H2SO4(aq) → Na2SO4(aq) + 2H2O(l) What is th
June 2022, AS Unit 2, Q10(b) (1 mark): A bottle of hydrogen peroxide is labelled as ‘10 volume’. This means that 1 cm3 of hydrogen peroxide solution decomposes to produce 10 cm3 oxygen at room temper
June 2022, AS Unit 2, Q15(b)(i) (3 marks): The gas syringe can measure a maximum of 100 cm3 of gas. Calculate the maximum volume of 0.500 mol dm−3 hydrochloric acid that can be added to excess calcium ca
June 2022, AS Unit 2, Q16(e) (3 marks): A sample of seawater was evaporated to dryness. The solid residue was weighed, then dissolved completely in deionised water. Excess aqueous silver nitrate was a
June 2022, AS Unit 2, Q17(d) (3 marks): Bromoethane is prepared by reacting ethanol with potassium bromide and concentrated sulfuric acid. C2H5OH + KBr + H2SO4 → C2H5Br + KHSO4 + H2O Calculate the max
June 2022, AS Unit 3, Q1(b)(i) (2 marks): Show by calculation that the zinc powder is in excess. (2)
June 2022, AS Unit 3, Q2(a) (4 marks): Calculate the value for the Ar of the metal M from the data of the first student. MHCO3 and HCl react in a 1 : 1 ratio. You must show your working. Give your an
June 2022, Unit 5, Q7(a) (1 mark): A repeat unit of the polymer PET has the structure shown. O O O O What is the percentage by mass of carbon in the repeat unit? (1) A 57.1 % B 62.5 % C 65.2 % D
June 2022, Unit 5, Q12(f) (4 marks): Calculate the volume of benzene required to form 5.92 g of 2‑ethanoylaminobenzoic acid, assuming the overall yield for the synthesis is 28.2 %. Give your answer
June 2022, Unit 5, Q14(a) (4 marks): Complete combustion of 6.02 g of Q produces 18.07 g of carbon dioxide and 3.30 g of water. Determine the empirical formula of Q. (4)
June 2022, Unit 6, Q4(b)(iii) (3 marks): A student obtained 1.20 cm3 of limonene. Calculate the amount, in moles, of limonene produced. (3)
January 2022, AS Unit 1, Q9 (1 mark): The concentration of nitrogen dioxide in a sample of air is 0.5 ppm. What is the percentage of nitrogen dioxide molecules in this sample of air? A 0.5 % B 0.005
January 2022, AS Unit 1, Q14 (1 mark): The equation for the complete combustion of hexane is shown. C6H14 + 9½ O2 ® 6CO2 + 7H2O How many molecules of carbon dioxide are formed when 2 × 10−3 mol of he
January 2022, AS Unit 1, Q16 (1 mark): Iron(III) oxide is reduced by hydrogen in a two-step process. Step 1: 3Fe2O3 + H2 ® 2Fe3O4 + H2O Step 2: Fe3O4 + 4H2 ® 3Fe + 4H2O What is the maximum mass of ir
January 2022, AS Unit 1, Q17 (1 mark): Which of these solutions contains the greatest number of ions? A 20.0 cm3 of 0.5 mol dm−3 KCl B 0.40 dm3 of 0.03 mol dm−3 KCl C 10.0 cm3 of 0.6 mol dm−3 CaCl2 D
January 2022, AS Unit 1, Q18 (1 mark): Potassium chlorate(V) decomposes on heating to form oxygen. 2KClO3 ® 2KCl + 3O2 What is the atom economy (by mass) for the formation of oxygen? [Ar values: O =
January 2022, AS Unit 1, Q19(a)(i) (1 mark): Complete the table of results. (1) Measurement Mass / g Mass of empty crucible 21.21 Mass of crucible and hydrated 26.71 magnesium sulfate before heating Mass o
January 2022, AS Unit 1, Q19(a)(ii) (4 marks): Use these results to calculate the value of x in MgSO4 · x H2O. Give your answer to the nearest whole number. [Ar values: H = 1.0 O = 16.0 Mg = 24.3 S = 32.1] (
January 2022, AS Unit 1, Q19(b) (2 marks): The correct value of x is greater than the value calculated in (a) (ii). Suggest a way of improving the method to obtain a more accurate result, using the same
January 2022, AS Unit 1, Q20(c)(ii) (4 marks): An experiment was carried out to produce pure, dry crystals of hydrated copper(II) sulfate, CuSO4 • 5H2O. Copper(II) carbonate was mixed with 50.0 cm3 of 1.00 m
January 2022, AS Unit 1, Q21(c)(iv) (3 marks): In an experiment, 0.050 mol of alpha-ocimene reacted with 3.6 dm3 of hydrogen, H2 , in the presence of a catalyst. Deduce the structure of the product of this r
January 2022, AS Unit 1, Q24(a) (4 marks): Calculate the molar mass of C. [ pV = nRT R = 8.31 J mol−1 K−1 ] (4)
January 2022, AS Unit 1, Q24(b) (1 mark): The organic liquid C is a hydrocarbon. Give a possible name or formula for C, using your answer in (a). (1)
January 2022, AS Unit 2, Q15 (1 mark): A titre of 13.25 cm3 was obtained using a 50 cm3 burette. What is the percentage uncertainty in the titre? [Each reading of the burette has an uncertainty of ±
January 2022, AS Unit 2, Q23(a)(ii) (4 marks): After heating a 6.0 g sample of magnesium ethanedioate for three minutes, the decomposition was 70 % complete. Calculate the total mass of the solid mixture tha
January 2022, AS Unit 2, Q24(b) (2 marks): A saturated solution of urea has a concentration of 9.07 mol dm–3 at 25 °C. Calculate the mass of urea in 150 cm3 of a saturated solution. (2)
January 2022, AS Unit 2, Q24(g)(ii) (3 marks): The chemical reactions in the exhaust system of a diesel car, using a catalytic converter, form 89.3 m3 of nitrogen per hour. Calculate the number of molecules
January 2022, AS Unit 3, Q2(a)(i) (2 marks): State the measurements that should be made. (2)
January 2022, AS Unit 3, Q2(a)(ii) (2 marks): Give two reasons why pure O2(g), and not air, should be used. (2)
January 2022, AS Unit 3, Q2(a)(iii) (3 marks): The experiment showed that 1.33 g of X contains 0.14 g of hydrogen and 0.63 g of carbon. Calculate the empirical formula of X, using these data. You must show y
January 2022, AS Unit 3, Q3(a)(ii) (1 mark): Give a possible reason why it is necessary to add sodium sulfate solution. Justify your answer. (1)
January 2022, AS Unit 3, Q3(c)(i) (2 marks): Complete the table and use the concordant results to calculate the mean titre. (2)
January 2022, AS Unit 3, Q3(c)(ii) (5 marks): Determine the value of x in the formula of the hydrated salt, BaCl2 · x H2O. Use information from the procedure and your mean titre from (c)(i). You must show y
January 2022, Unit 4, Q20(b)(i) (3 marks): Compound A is thought to be another isomer of hexanoic acid. 10 g of compound A is found to contain 6.21 g of carbon and 1.03 g of hydrogen, with the remainder
January 2022, Unit 5, Q4 (1 mark): A mass of 4.179 g of hydrated iron(III) sulfate, Fe2(SO4)3·H2O , was dissolved in deionised water and the solution made up to 200 cm3. 2− , in the solution, in
January 2022, Unit 5, Q16(c) (6 marks): Hydrated calcium benzoate is used as a preservative in soft drinks. It has the formula Ca(C6H5COO)2·xH2O. 2.60 g of hydrated calcium benzoate was dissolved in d
January 2022, Unit 6, Q4(h) (4 marks): This question is about the preparation of phenylamine by the reduction of nitrobenzene. NH2 NO2 + 6[H] → + 2H2O phenylamine nitrobenzene Outline procedure Step
October 2021, AS Unit 1, Q1(a) (1 mark): What is this concentration of sulfur in ppm? (1) A 0.00001 B 0.01 C 10 D 10 000
October 2021, AS Unit 1, Q1(b) (1 mark): 3.2 kg of this diesel fuel is burned in air. What is the maximum volume, in dm3, of sulfur dioxide which can be produced, measured at room temperature and press
October 2021, AS Unit 1, Q4(a) (1 mark): What is the concentration, in mol dm−3, of sodium hydroxide in the solution formed? (1) A 0.010 B 0.029 C 0.29 D 0.66
October 2021, AS Unit 1, Q4(b) (1 mark): What is the maximum volume, in cm3, of hydrogen which could be formed, measured at r.t.p.? [Molar volume of a gas at r.t.p. = 24 dm3 mol−1] (1) A 120 B 240 C 48
October 2021, AS Unit 1, Q4(d) (1 mark): Sodium hydroxide solution was added to magnesium sulfate solution. The equation for the reaction is shown. 2NaOH(aq) + MgSO4(aq) → Mg(OH)2(s) + Na2SO4(aq) What
October 2021, AS Unit 1, Q13(c) (3 marks): Calcium silicate is formed in the removal of silicon dioxide impurities in the extraction of iron from its ores. A sample of calcium silicate composed of calciu
October 2021, AS Unit 1, Q13(d) (4 marks): Carbon dioxide is a gas at room temperature. A fizzy drink is canned at 5.0 °C and 1.3 × 105 Pa and contains approximately 3 g of carbon dioxide. Calculate the
October 2021, AS Unit 1, Q15(e)(i) (3 marks): Butane is used as a fuel. The equation for the complete combustion of butane is shown. 2C4H10(g) + 13O2(g) → 8CO2(g) + 10H2O(l) 35.0 cm3 butane is completely bu
October 2021, AS Unit 2, Q9 (1 mark): The equation for the complete combustion of propan-1-ol is shown. C3H7OH(l) + 4½O2(g) ® 3CO2(g) + 4H2O(l) 2.00 × 10−3 mol of propan-1-ol undergoes complete comb
October 2021, AS Unit 2, Q13 (1 mark): A student is provided with 25.0 cm3 of 1.00 mol dm–3 hydrochloric acid. What volume of distilled water should the student add to this solution to make a 0.0500
October 2021, AS Unit 2, Q18 (1 mark): 10.00 g of hydrated magnesium sulfate, MgSO4.7H2O, is heated to remove the water of crystallisation. What mass of anhydrous magnesium sulfate, MgSO4 , is formed
October 2021, AS Unit 2, Q19(a)(i) (1 mark): Calculate the number of moles of ethanol in 1.19 g. [ Molar mass of ethanol = 46.0 g mol−1 ] (1)
October 2021, AS Unit 2, Q21(b)(i) (2 marks): The indicator used was phenolphthalein. State the colour change at the end-point. (2) from to
October 2021, AS Unit 2, Q21(b)(ii) (4 marks): Calculate the relative atomic mass of M and use it to identify the Group 1 metal, M. (4)
October 2021, AS Unit 2, Q21(c) (2 marks): Another student repeated the experiment, using a different sample of metal M, but did not wipe off the oil before weighing it. State how this would change the c
October 2021, AS Unit 3, Q5(a) (1 mark): Complete the titre values. (1) Titration number Rough 1 2 3 4 Final reading 24.90 21.25 42.85 21.80 43.15 / cm3 Initial reading 2.30 0.00 21.25 0.50 21.80 / cm3
October 2021, AS Unit 3, Q5(b)(i) (1 mark): State why the value from Titration 2 was not used to calculate the mean. (1)
October 2021, AS Unit 3, Q5(b)(ii) (4 marks): Calculate the concentration of the sodium hydroxide solution in mol dm−3. (4)
October 2021, AS Unit 3, Q5(d) (2 marks): State the colour change that would be seen at the end-point in this titration using phenolphthalein as the indicator. (2) From to
October 2021, Unit 4, Q16(a)(i) (1 mark): Give a reason why the oxygen used must be dry. (1)
October 2021, Unit 4, Q16(a)(ii) (5 marks): Show that the empirical formula of X is C4H6O3 . You must show your working. (5)
October 2021, Unit 5, Q18(a) (2 marks): Deduce the formula of the hydrated salt A. You must show your working. (2)
October 2021, Unit 5, Q18(d) (3 marks): The percentage composition by mass of salt E is K = 35.6 % Fe = 17.0 % C = 21.9 % N = 25.5 % Calculate the empirical formula of salt E. (3)
October 2021, Unit 5, Q21(e)(ii) (3 marks): Calculate the mass of 2‑nitrobenzaldehyde required to make 10.0 g of indigotin from this reaction when the percentage yield is 85.0 % . (3)
June 2021, AS Unit 1, Q15 (1 mark): Cyclohexene may be prepared by the dehydration of cyclohexanol. OH + H2O cyclohexanol cyclohexene Mr = 100 Mr = 82 What mass of cyclohexene can be made from 12.
June 2021, AS Unit 1, Q16 (1 mark): Which of these gases occupies 6.0 dm3 at room temperature and pressure (r.t.p.)? [molar volume of gas at r.t.p. = 24.0 dm3 mol−1 Ar values: He = 4.0 C = 12.0 N
June 2021, AS Unit 1, Q17 (1 mark): An oxide of lead contains 90.7 % by mass of lead. What is the formula of this oxide? [Ar values: O = 16.0 Pb = 207.2] A PbO B PbO2 C Pb2O3 D Pb3O4
June 2021, AS Unit 1, Q18 (1 mark): Propane burns completely in oxygen as shown. C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(l) 100 cm3 of propane was mixed with 600 cm3 of oxygen and the mixture was ignite
June 2021, AS Unit 1, Q19 (1 mark): Which aqueous solution contains the greatest number of ions? A 200 cm3 of 1.5 mol dm−3 MgCl2 B 400 cm3 of 0.8 mol dm−3 MgSO4 C 500 cm3 of 1.0 mol dm−3 NaCl D 10
June 2021, AS Unit 1, Q20 (1 mark): A sample of seawater with a mass of 1 kg contains 6 × 10−9 g of gold. How many atoms of gold, to one significant figure, are there in 1 g of this seawater? [Ar
June 2021, AS Unit 1, Q23(f) (4 marks): 0.0100 mol of an alkene reacts completely with exactly 600 cm3 of hydrogen gas, measured at 298 K and 1.24 × 105 Pa pressure, to form an alkane. Use the ideal g
June 2021, AS Unit 1, Q24(d) (3 marks): 25.00 g of a compound contains 6.98 g of iron and 6.03 g of sulfur. The remaining mass is oxygen. Calculate the empirical formula of this compound. [Ar values:
June 2021, AS Unit 1, Q24(e) (5 marks): When 6.95 g of FeSO4.xH2O is heated, 2.00 g of iron(III) oxide, 0.80 g of sulfur dioxide and 1.00 g of sulfur trioxide are produced. The only other product is w
June 2021, AS Unit 2, Q14 (1 mark): A 4.00 mol dm−3 solution of an acid is used to prepare dilute solutions of the acid. What volume of water is required to make up 150 cm3 of 0.35 mol dm−3 soluti
June 2021, AS Unit 2, Q15(a) (1 mark): A pellet of sodium hydroxide has a mass of 0.700 g. Some pellets were dissolved to make 350 cm3 of 0.25 mol dm–3 solution. [Mr value: NaOH = 40] How many pellet
June 2021, AS Unit 2, Q15(b) (1 mark): 25.0 cm3 of the sodium hydroxide solution prepared in (a) was placed in a conical flask and titrated with sulfuric acid. 2NaOH + H2SO4 → Na2SO4 + 2H2O Calculate
June 2021, AS Unit 2, Q15(c) (1 mark): Phenolphthalein indicator was used for the titration in (b). What was the colour change at the endpoint? (1) A colourless → pink B pink → colourless C orange →
June 2021, AS Unit 2, Q21(a) (4 marks): A 6.0 g sample of magnesium oxalate was heated for three minutes but the decomposition was only 70 % complete. Calculate the total mass of solid that remains. (
June 2021, AS Unit 2, Q21(c) (1 mark): Suggest why a pure sample of magnesium carbonate will not be produced from the decomposition of magnesium oxalate even if the sample is heated for longer. (1)
June 2021, AS Unit 3, Q3(a) (2 marks): State the colour change observed at the end-point of the titration. (2) From to
June 2021, AS Unit 3, Q3(b)(i) (1 mark): Complete the table. (1)
June 2021, AS Unit 3, Q3(b)(ii) (1 mark): Give a reason why the first titre should not be used to calculate the mean titre. (1)
June 2021, AS Unit 3, Q3(b)(iii) (2 marks): Calculate the number of moles of hydrochloric acid in the mean titre. (2)
June 2021, AS Unit 3, Q3(b)(iv) (3 marks): The equation for the reaction in the titration is Ba(OH)2(aq) + 2HCl(aq) → BaCl2(aq) + 2H2O(l) Calculate the concentration of barium hydroxide, in g dm−3, givin
June 2021, AS Unit 3, Q4(e)(i) (1 mark): Give one possible reason for the yield being less than 100 %. (1)
June 2021, AS Unit 3, Q4(e)(ii) (4 marks): After some research the student decided to use 21.0 g of butan-1-ol to prepare 20 cm3 of 1-bromobutane. Calculate the percentage yield that the student expected
June 2021, Unit 4, Q17(a) (2 marks): Y contains 66.7% carbon, 11.1% hydrogen and 22.2% oxygen by mass. Show that these data are consistent with its molecular formula. (2)
June 2021, Unit 5, Q17 (1 mark): What is the minimum volume of oxygen gas, measured at room temperature and pressure, required for the complete combustion of 9.2 g of C3H8O3 (Mr = 92)? [Molar v
June 2021, Unit 5, Q19(a)(ii) (4 marks): When 0.493 g of X was vaporised, 157 cm3 of dry air was displaced, measured at 15°C and 103 000 Pa. Calculate the molar mass of X, using the ideal gas equation.
June 2021, Unit 5, Q19(b)(iii) (3 marks): Analysis of Y showed that its composition by mass was 62.6 % carbon; 11.3 % hydrogen; 12.2 % nitrogen; 13.9 % oxygen. Determine the empirical formula of Y. You
June 2021, Unit 6, Q2(g)(i) (3 marks): Calculate the apparent percentage yield of Cu(NH3)4SO4.H2O. Give your answer to an appropriate number of significant figures. (3)
June 2021, Unit 6, Q3(d)(ii) (4 marks): Calculate the empirical formula of the compound, using the data given. You must show your working. (4)
June 2021, Unit 6, Q3(d)(iv) (1 mark): Deduce the molecular formula of the compound, using your answers to (ii) and (d)(iii). (1)
January 2021, AS Unit 1, Q3 (1 mark): Which aqueous solution has the highest concentration, in mol dm-3, of chloride ions? A 0.1 g dm-3 HCl B 0.1 g dm-3 NaCl C 0.1 g dm-3 KCl D 0.1 g dm-3 BaCl2
January 2021, AS Unit 1, Q4 (1 mark): Which conversion has the lowest percentage atom economy (by mass) for the formation of CaCl2? A Ca + Cl2 → CaCl2 B Ca + 2HCl → CaCl2 + H2 C CaCO3 + 2HCl → CaCl2
January 2021, AS Unit 1, Q21(c)(ii) (1 mark): Squalane used in cosmetic products must contain no more than 0.2 ppm by mass of catalyst. Calculate the maximum permitted mass of catalyst in a product containi
January 2021, AS Unit 1, Q21(c)(iii) (4 marks): A reactor at 200°C contains 8500 mol of liquid squalene, and hydrogen gas at a pressure of 4.0 × 105 Pa. Under these conditions, the complete hydrogenation of s
January 2021, AS Unit 1, Q21(d)(ii) (2 marks): Calculate the minimum number of sharks that would be needed to produce 2.8 million dm3 of squalene. [Density of squalene = 0.86 g cm-3] (2)
January 2021, AS Unit 1, Q21(d)(iii) (3 marks): Many large corporations now use squalane obtained entirely from plants. Squalane can be obtained sustainably from corn starch with a yield of 23 % by mass. The
January 2021, AS Unit 2, Q15 (1 mark): Magnesium nitrate decomposes on heating. 2Mg(NO3)2 → 2MgO + 4NO2 + O2 What is the total volume of gas formed at room temperature and pressure (r.t.p.) when 0.00
January 2021, AS Unit 2, Q16 (1 mark): How many moles are there in 15.1 cm3 of liquid propan-1-ol? [Density of propan-1-ol = 0.80 g cm−3 Mr of propan-1-ol = 60] A (0.80 × 15.1) ÷ 60 B 0.80 ÷ (60 × 15
January 2021, AS Unit 2, Q17 (1 mark): The oxidation of propan-1-ol by acidified potassium dichromate(VI) forms propanoic acid with a yield of 36 % by mass. What mass of propan-1-ol is needed to form
January 2021, AS Unit 2, Q18 (1 mark): Barium chloride solution, BaCl2(aq), reacts with gallium sulfate solution, Ga2(SO4)3(aq) to form a precipitate of barium sulfate, BaSO4(s). What is the minimum
January 2021, AS Unit 2, Q21(d) (2 marks): Ammonium carbonate, (NH4)2CO3 , is an ingredient in cleaning solutions for camera lenses. These are aqueous solutions which contain no more than 1.8 g of ammoni
January 2021, AS Unit 2, Q22(a)(ii) (3 marks): Calculate the overall atom economy by mass for the production of potassium chlorate(V), KClO3 , using your equation in (a)(i). (3)
January 2021, AS Unit 2, Q22(c)(ii) (5 marks): 1.52 g of impure potassium chlorate(V), formed in the Liebig Process, was heated until the mass of solid remaining was constant at 1.02 g. The reaction that occ
January 2021, AS Unit 3, Q2(a)(i) (1 mark): Give a possible reason why any solution remaining in the beaker is washed into the volumetric flask before making up to the mark. (1)
January 2021, AS Unit 3, Q2(a)(ii) (2 marks): Calculate the concentration of this standard solution of ethanedioic acid in mol dm–3. Give your answer to an appropriate number of significant figures. [Molar
January 2021, AS Unit 3, Q2(b)(i) (1 mark): Explain why the burette is rinsed with ethanedioic acid solution in Step 2. (1)
January 2021, AS Unit 3, Q2(b)(iv) (2 marks): State the colour change in the conical flask at the end-point. (2) From to
January 2021, AS Unit 3, Q2(c)(i) (2 marks): Complete the table and calculate the mean titre. (2)
January 2021, AS Unit 3, Q2(c)(ii) (3 marks): Calculate the concentration of the sodium hydroxide solution in mol dm–3. The equation for the titration is (COOH)2 + 2NaOH → (COONa)2 + 2H2O (3)
January 2021, AS Unit 3, Q3(b)(i) (3 marks): Using the results of the experiment identify the Group 2 metal. [Molar volume of gas at room temperature and pressure = 24.0 dm3 mol−1 ] (3)
January 2021, AS Unit 3, Q4(b) (3 marks): The equation for the reaction is (CH3)3COH(l) + HCl(aq) → (CH3)3CCl(l) + H2O(l) The final product after distillation weighed 2.62 g. Calculate the percentage yi
January 2021, Unit 4, Q15 (1 mark): 2.95 g of ethanoic acid is produced from 2.50 g of ethanol. What is the percentage yield of ethanoic acid? [Molar masses in g mol−1: ethanoic acid = 60 ethanol
January 2021, Unit 4, Q18(b)(i) (2 marks): Commercial concentrated sulfuric acid contains 98.5 % H2SO4 and 1.5 % water by mass. The density of concentrated sulfuric acid is 1800 g dm−3. Calculate the con
January 2021, Unit 5, Q24(b)(i) (4 marks): Calculate the concentration, in mol dm−3, of caffeine in this cup of coffee. Give your answer to an appropriate number of significant figures. (4)
January 2021, Unit 6, Q2(b) (2 marks): The reaction in Step 2 produced 0.430 g of a white precipitate of silver chloride, AgCl. Calculate the concentration of KClO3 in the solution, in mol dm–3, foun
October 2020, AS Unit 1, Q4 (1 mark): A compound has Mr = 84 and its composition by mass is 71.4 % carbon, 9.6 % hydrogen and 19.0 % oxygen. What is the molecular formula of this compound? [ Ar valu
October 2020, AS Unit 1, Q12 (1 mark): What is the percentage atom economy, by mass, for the production of hydrogen in the reaction shown? CH4 + H2O → CO + 3H2 [Ar values: H = 1.00 C = 12.0 O = 16.0]
October 2020, AS Unit 1, Q19(b) (4 marks): When 0.00100 mol of ammonium dichromate(VI) was heated, 25.2 cm3 of nitrogen gas, measured at laboratory temperature, was formed. Calculate the temperature in t
October 2020, AS Unit 1, Q21(a) (2 marks): Calculate the volume, in cm3, of 0.0300 mol of cyclohexene. Give your answer to an appropriate number of significant figures. You must show your working. Data A
October 2020, AS Unit 1, Q21(c)(i) (1 mark): State the meaning of ppm. (1)
October 2020, AS Unit 1, Q21(c)(ii) (3 marks): A sample of 3.25 cm3 of bromine vapour leaks into a laboratory. Calculate the minimum volume, in dm3, of the laboratory for the resulting concentration of bromi
October 2020, AS Unit 1, Q21(d) (3 marks): Because bromine is so hazardous it is usually used in the laboratory in aqueous solution. A sample of bromine reacts with exactly 0.0300 mol of cyclohexene. Cal
October 2020, AS Unit 2, Q11(a) (1 mark): What is the total volume (at r.t.p.) of carbon dioxide formed? [Mr(MgCO3) = 84.3 Molar volume of a gas at r.t.p. = 24.0 dm3 mol–1] (1) A 2.40 dm3 B 1.20 dm3 C 2
October 2020, AS Unit 2, Q14(b) (4 marks): The concentration of a saturated solution of calcium hydroxide can be determined by titration. 25.0 cm3 portions of a saturated solution of calcium hydroxide we
October 2020, AS Unit 2, Q15(b)(ii) (2 marks): Student B used a gravimetric method, which involved weighing a product of a reaction. A 50.0 cm3 sample of the same silver nitrate solution was mixed with exces
October 2020, AS Unit 2, Q17(c)(ii) (1 mark): Calculate the mass of carbon dioxide released when 1 mol of octane (C8H18) is burned completely. (1)
October 2020, AS Unit 2, Q17(c)(iii) (2 marks): A motorist who uses 1200 kg of fuel each year in a car changes to a fuel with 5% of the mass of petrol replaced by methanol produced by CCU. Calculate the annua
October 2020, AS Unit 3, Q5(b) (2 marks): Methyl orange indicator was used in this titration. Give the colour change in the conical flask at the end-point. (2) Colour change from to
October 2020, AS Unit 3, Q5(c)(i) (1 mark): Complete the table. (1)
October 2020, AS Unit 3, Q5(c)(ii) (1 mark): Using appropriate titrations, calculate the mean titre. (1)
October 2020, AS Unit 3, Q5(c)(iii) (1 mark): Using your answer to (c)(ii), calculate the number of moles of HCl in the mean titre. (1)
October 2020, AS Unit 3, Q5(c)(iv) (2 marks): Calculate the number of moles of M2CO3 in 25.0 cm3 of the solution. Hence calculate the number of moles of M2CO3 in the 250.0 cm3 volumetric flask. (2)
October 2020, AS Unit 3, Q5(c)(v) (1 mark): Using your answer in (c)(iv) and the mass of M2CO3.10H2O in the 250 cm3 of solution, calculate the molar mass of M2CO3.10H2O. (1)
October 2020, AS Unit 3, Q5(c)(vi) (2 marks): Use your answer to (c)(v) to identify metal M. (2)
October 2020, Unit 4, Q13 (1 mark): In which of these esters is the percentage by mass of carbon 54.5 %? A methyl methanoate, HCOOCH3 B methyl ethanoate, CH3COOCH3 C ethyl ethanoate, CH3COOCH2CH3
October 2020, Unit 5, Q6 (1 mark): Phenol reacts with ethanoyl chloride to form phenyl ethanoate. OH O CH3 C + CH3COCl + HCl O phenol phenyl ethanoate Mr = 94 Mr = 136 In an experiment, 3.67 g of
October 2020, Unit 5, Q7 (1 mark): A hydrocarbon contains 91.3 % by mass of carbon. Which of these could be the molecular formula of this compound? A C6H6 B C7H8 C C8H10 D C9H12
October 2020, Unit 5, Q20 (1 mark): A solution contains 19.6 g dm−3 of chromium(III) sulfate, Cr2(SO4)3 . What is the concentration, in mol dm–3, of sulfate ions in this solution? [Molar mass Cr2(
October 2020, Unit 5, Q23(a) (4 marks): A mixture of methane and ethane with a total volume of 25.0 cm3 required 65.0 cm3 of oxygen for complete combustion. All gas volumes were measured at the same t
October 2020, Unit 5, Q25(e)(i) (3 marks): The Lanthanides The lanthanides form a series in the Periodic Table comprising the elements from lanthanum, La (Z = 57) to lutetium, Lu (Z = 71). They have impo
October 2020, Unit 6, Q4(c) (3 marks): Show, by calculation, that the ethanoic anhydride is in excess in this preparation. (3)
January 2020, AS Unit 1, Q7 (1 mark): An 11.0 g sample of anhydrous sodium sulfate, Na2SO4 , is dissolved in deionised water to form 70 cm3 of solution. What is the concentration, in mol dm–3, of Na
January 2020, AS Unit 1, Q10(c) (1 mark): What is the maximum mass of BaSO4 that could be produced from 0.500 g of BaCl2 in this reaction? (1) A 0.446 g B 0.500 g C 0.560 g D 0.821 g
January 2020, AS Unit 1, Q10(d) (1 mark): What is the atom economy (by mass) for the formation of BaSO4 in this reaction? (1) A 33.3% B 62.2% C 66.6% D 80.0%
January 2020, AS Unit 1, Q20(b)(iv) (3 marks): Calculate the percentage by mass of bromine in the heaviest molecule containing six carbon atoms that could form when hexane reacts with a large excess of bromi
January 2020, AS Unit 1, Q21(b) (5 marks): Ethene is used commercially to speed up the ripening of bananas. Ethene levels of 100 parts per million (ppm) are used in ripening rooms. Calculate the amount,
January 2020, AS Unit 1, Q21(d)(i) (2 marks): When 10.0 g of ethene reacts completely with oxygen, the mass of compound Y formed is 15.7 g. Calculate the empirical formula of Y. You must show your working.
January 2020, AS Unit 2, Q4 (1 mark): How many moles of CO2 are formed when 3.0 mol of chloroethene, C2H3Cl, is mixed with 10.0 mol of oxygen and react as shown? 2C2H3Cl + 5O2 → 4CO2 + 2H2O + 2HCl A
January 2020, AS Unit 2, Q10(b) (1 mark): What is the percentage atom economy by mass for the production of silver iodide in this reaction? (1) A 29 % B 37 % C 50 % D 73 % Use this space for any rough w
January 2020, AS Unit 2, Q12(a) (1 mark): What is the final volume of the mixture of gases in dm3 at r.t.p.? (1) A 9.60 B 11.2 C 21.6 D 23.2
January 2020, AS Unit 2, Q12(b) (1 mark): If the final mixture of gases is passed through a U-tube containing sodium hydroxide, what is the final volume of gas in cm3? (1) A 0.0 B 1600 C 9600 D 12000 Us
January 2020, AS Unit 2, Q15(d)(i) (2 marks): Calculate the amount, in moles, of sodium carbonate in the 250.0 cm3 of solution. (2)
January 2020, AS Unit 2, Q15(d)(ii) (4 marks): The 250.0 cm3 of solution was prepared by dissolving 3.29 g of Na2CO3.xH2O. Use this mass and your answer to (d)(i) to determine the value of x. Give your answe
January 2020, AS Unit 2, Q18(a) (2 marks): Calculate the percentage by mass of nitrogen in urea. (2)
January 2020, AS Unit 2, Q18(b) (2 marks): Urea is supplied as solid pellets and is used widely in Africa and Asia, particularly in the cultivation of crops such as rice which are grown in fields immerse
January 2020, AS Unit 3, Q3(a) (2 marks): The indicator used was methyl orange. State the colour change at the end-point. (2) From to
January 2020, AS Unit 3, Q3(b)(i) (2 marks): Complete the table and, using appropriate titrations, calculate the mean titre. (2)
January 2020, AS Unit 3, Q3(b)(ii) (5 marks): Calculate the percentage purity, by mass, of the sodium carbonate. (5)
June 2019, AS Unit 1, Q6 (1 mark): In 1.31 g of a chloride of titanium, there is 0.528 g of titanium. What is the empirical formula of this titanium chloride? [ Ar values: Ti = 47.9 Cl = 35.5 ] A
June 2019, AS Unit 1, Q21(b)(i) (3 marks): Plot a graph of these results. (3)
June 2019, AS Unit 1, Q21(b)(ii) (1 mark): A student carried out a further experiment using a different mass of magnesium carbonate. Give the volume of gas collected using the inverted measuring cylinder
June 2019, AS Unit 1, Q21(b)(iii) (1 mark): Determine the mass of magnesium carbonate added in the experiment in (ii), using your graph. (1)
June 2019, AS Unit 1, Q21(b)(iv) (4 marks): Calculate the molar volume of carbon dioxide using your answers to parts (b)(ii) and (b)(iii). Give your value to an appropriate number of significant figures a
June 2019, AS Unit 1, Q21(b)(v) (2 marks): The acid must be in excess for each experiment. Calculate the minimum concentration of hydrochloric acid needed for 30 cm3 of acid to completely react with 0.25
June 2019, AS Unit 1, Q21(c) (2 marks): The value of molar volume calculated in (b)(iv) was lower than the student expected. Give two reasons for the value being lower than expected. Assume that the c
June 2019, AS Unit 1, Q24(b) (6 marks): A passenger airbag requires 120 dm3 of gas to fill it. Calculate, using the ideal gas equation, the mass of sodium azide required to fill a passenger airbag in
June 2019, AS Unit 1, Q24(c)(i) (3 marks): Reaction A produces more nitrogen to inflate the airbag. Calculate the atom economy, by mass, for the production of nitrogen in reaction A. Give your answer to
June 2019, AS Unit 2, Q20(a)(i) (1 mark): State why the student used a warm oven to remove the water from the hydrated salt, rather than direct heating with a Bunsen burner. (1)
June 2019, AS Unit 2, Q20(a)(ii) (4 marks): Use the data obtained by the student to calculate the value of x. You must show your working. (4)
June 2019, AS Unit 2, Q21(b) (4 marks): A student carried out the reaction. After separation and purification, the mass of butan-1-ol formed was 12.1 g. The yield of the reaction was 64.0 %. Calculate
June 2019, AS Unit 2, Q23(d)(i) (2 marks): Phenolphthalein is a suitable indicator for this titration. State the colour change at the end-point. (2)
June 2019, AS Unit 2, Q23(d)(ii) (2 marks): Suggest two possible reasons why the titre for Run 1 is greater than the other two titres. (2)
June 2019, AS Unit 2, Q23(d)(iii) (5 marks): The equation for the reaction of propanoic acid with sodium hydroxide is CH3CH2COOH + NaOH → CH3CH2COONa + H2O Calculate the mass in grams of propanoic acid ext
June 2019, AS Unit 2, Q23(d)(iv) (2 marks): Use your answer to (d)(iii) to determine whether the acid in this sample lies within the permitted range for use in animal feed. (2)
June 2019, AS Unit 2, Q23(d)(v) (1 mark): Suggest how the animal feed would be affected if the amount of propanoic acid was outside the permitted range. (1)
June 2019, AS Unit 3, Q3(b)(iii) (3 marks): The equation for the reaction of M with copper(II) sulfate is M(s) + CuSO4(aq) → MSO4(aq) + Cu(s) Use the equation and your answer to (b)(ii) to calculate the r
June 2019, AS Unit 3, Q4(a) (1 mark): State what is meant by the term ‘concordant results’. (1)
June 2019, AS Unit 3, Q4(b) (1 mark): Using appropriate titres, calculate the mean titre. (1)
June 2019, AS Unit 3, Q4(c) (2 marks): State the colour change at the endpoint of the titration. (2) From to
June 2019, AS Unit 3, Q4(d) (4 marks): The equation for the reaction is NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l) Calculate the purity of the sodium hydroxide, NaOH, as a percentage by mass. (4)
January 2019, AS Unit 1, Q18 (1 mark): What mass of anhydrous sodium carbonate is needed to make 50.0 cm3 of a 0.0800 mol dm−3 solution of sodium carbonate, Na2CO3? [Ar values: C = 12.0, O = 16.0, Na
January 2019, AS Unit 1, Q19 (1 mark): A sample of air, with a mass of 5.0 kg, contained carbon monoxide with a concentration of 12 parts per million by mass. What is the mass of carbon monoxide in t
January 2019, AS Unit 1, Q20 (1 mark): What is the maximum volume of hydrogen formed, at room temperature and pressure (r.t.p.), when 0.207 g of lithium is added to excess water? 2Li(s) + 2H2O(l) o 2
January 2019, AS Unit 1, Q22(b)(iii) (4 marks): A sample of nitrogen gas occupied 108 cm3 at a temperature of 25 °C and a pressure of 1.36 × 105 Pa. Using the ideal gas equation, calculate the number of moles
January 2019, AS Unit 1, Q23(f) (4 marks): A sample of 2-methylpropene was prepared from 2-methylpropan-2-ol. + H2O OH 2-methylpropan-2-ol 2-methylpropene Mr = 74.0 Mr = 56.0 The yield of this reaction w
January 2019, AS Unit 1, Q24(b) (3 marks): A sample of a compound is analysed and found to contain only 3.09 g carbon, 0.26 g hydrogen and 9.15 g chlorine. The molar mass of the compound is 97.0 g mol−1.

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