Chemical calculations: Eduqas A‑Level Chemistry questions

Every Eduqas A-Level Chemistry exam question on C1.3 Chemical calculations, 2016–2025, with its mark scheme and examiner’s report.

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1,513 questions

Q10(d)(i)
June 2025 · Component 1
2 marksC1.3 Chemical calculations
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Q11(c)(i)
June 2025 · Component 1
2 marksC1.3 Chemical calculations
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Q11(c)(ii)
June 2025 · Component 1
2 marksC1.3 Chemical calculations
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Q11(c)(iii)
June 2025 · Component 1
3 marksC1.3 Chemical calculations
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Q11(c)(iv)
June 2025 · Component 1
3 marksC1.3 Chemical calculations
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Q13(b)(i)
June 2025 · Component 1
2 marksC1.3 Chemical calculations
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Q13(b)(ii)
June 2025 · Component 1
1 markC1.3 Chemical calculations
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Q13(b)(iii)
June 2025 · Component 1
5 marksC1.3 Chemical calculations
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Q13(b)(iv)
June 2025 · Component 1
4 marksC1.3 Chemical calculations
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Q3(a)
June 2025 · Component 2
1 markC1.3 Chemical calculations
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Q7(a)(i)
June 2025 · Component 2
2 marksC1.3 Chemical calculations
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Q7(a)(ii)
June 2025 · Component 2
1 markC1.3 Chemical calculations
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Q8(c)(i)
June 2025 · Component 2
3 marksC1.3 Chemical calculations
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Q9(c)(i)
June 2025 · Component 2
2 marksC1.3 Chemical calculations
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Q10(a)(iv)
June 2025 · Component 2
2 marksC1.3 Chemical calculations
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Q11(a)(v)
June 2025 · Component 2
2 marksC1.3 Chemical calculations
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Q11(e)(ii)
June 2025 · Component 2
2 marksC1.3 Chemical calculations
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Q12(a)(iv)
June 2025 · Component 2
1 markC1.3 Chemical calculations
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Q12(d)
June 2025 · Component 2
2 marksC1.3 Chemical calculations
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Q2(f)
June 2025 · Component 3
3 marksC1.3 Chemical calculations
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All 235 questions on Chemical calculations, as a list

June 2025, Component 1, Q10(d)(i) (2 marks): The tin mined in Cornwall included the mineral cassiterite. Cassiterite is an oxide of tin that contains 78.8% tin by mass. Find the formula of this oxide. You
June 2025, Component 1, Q11(c)(i) (2 marks): Find the value of d. [2] d = ………………...………………
June 2025, Component 1, Q11(c)(ii) (2 marks): Find the relative formula mass, Mr, of gaylussite. [2] Mr = ………………...………………
June 2025, Component 1, Q11(c)(iii) (3 marks): Find the value of c. [3] c = ………………...………………
June 2025, Component 1, Q11(c)(iv) (3 marks): Use your answers to parts (i), (ii) and (iii) to deduce the identity of metal M and hence write the formula of gaylussite. [3] M is ………………...……… ……… Formula of
June 2025, Component 1, Q13(b)(i) (2 marks): One interhalogen ion is crystallised as a potassium salt and the Mr of this compound is found to be 373. Identify the formula of this interhalogen salt. [2] For
June 2025, Component 1, Q13(b)(ii) (1 mark): The interhalogen ions have a negative charge so it is difficult to use a traditional mass spectrometer to measure their mass. Suggest one adaptation to a mass s
June 2025, Component 1, Q13(b)(iii) (5 marks): The spectrum of the interhalogen ion Br2I– contains three peaks with masses of 285, 287 and 289. Assume that all the iodine atoms present are iodine-127. I. Sho
June 2025, Component 1, Q13(b)(iv) (4 marks): The interhalogen compound ClF3 is a gas at a particular temperature. The density of the gas is found to be 3.60 g dm–3 at a pressure of 1 atm. Calculate the tem
June 2025, Component 2, Q3(a) (1 mark): Calculate the relative molecular mass of this compound. [1] Mr =
June 2025, Component 2, Q7(a)(i) (2 marks): Calculate the relative molecular mass of compound W. [2] Mr =
June 2025, Component 2, Q7(a)(ii) (1 mark): Deduce the molecular formula of compound W. [1] Molecular formula
June 2025, Component 2, Q8(c)(i) (3 marks): Addition of water to 11.76 g of compound T hydrolysed only the acid chloride group. The resulting mixture was treated with aqueous silver nitrate, giving 8.61 g
June 2025, Component 2, Q9(c)(i) (2 marks): In a reaction, 6.90 g of 2-hydroxybenzoic acid was heated. Calculate the mass of phenol produced if the yield is 60%. [2] Mass = g
June 2025, Component 2, Q10(a)(iv) (2 marks): A gas-liquid chromatogram of the products shows the presence of 1-bromohexane and 2-bromohexane (Mr 165) and some unreacted hex-1-ene. Analysis of the mixture s
June 2025, Component 2, Q11(a)(v) (2 marks): Amides, such as pivalamide, react with an alkaline solution of bromine producing an amine. O NaOH / Br2 (CH3)3C C (CH3)3C NH2 NH2 Mr 73 In a reaction, 0.10 mol
June 2025, Component 2, Q11(e)(ii) (2 marks): Another product of this reaction is a chlorine-containing propanoic acid that contains 49.7% chlorine by mass. Show that this compound could be 2,2-dichloroprop
June 2025, Component 2, Q12(a)(iv) (1 mark): Butane-1,4-dioic acid is produced by the reaction of aqueous furfural and hydrogen peroxide. COOH CH2 O + 2H2O2 + HCOOH O CH2 H COOH Calculate the atom economy
June 2025, Component 2, Q12(d) (2 marks): The concentration of phenols in dilute aqueous solutions can be found using colorimetry. Analysis of a sewage sample showed that the concentration of 4-nitrophe
June 2025, Component 3, Q2(f) (3 marks): Calculate the percentage purity of the 1-bromobutane (Mr 137) based on the mass of dry silver bromide formed. [3] Percentage
June 2025, Component 3, Q2(g) (3 marks): Another student repeated the gravimetric analysis. This student’s percentage purity value was slightly higher than the value c
June 2025, Component 3, Q3(c) (2 marks): In a typical reaction, 172.6 g of benzenecarboxylic acid is converted to N-propylbenzamide. If the percentage yield for the conversion is 52.6%, calculate the m
June 2025, Component 3, Q4(a) (3 marks): Use the data from experiment 1 to calculate the value of b, the number of carbonate ions in each formula unit. [3] b =
June 2025, Component 3, Q4(c) (1 mark): 55.3% of the mass of each formula unit is due to copper ions. Use this information and the value of a given in part (b)(ii) to calculate the relative formula ma
June 2025, Component 3, Q4(d) (3 marks): Use all the information to find the formula of azurite. [3] Formula
June 2025, AS Component 1, Q5 (2 marks): An oxide of phosphorus was analysed and was found to contain 49.3% phosphorus and 50.7% oxygen by mass. Determine the empirical formula of this compound. [2] Em
June 2025, AS Component 1, Q9(d) (2 marks): Naturally occurring chromium has four stable isotopes. Calculate its relative atomic mass using the following information. Show your working and give your answe
June 2025, AS Component 1, Q10(b)(i) (3 marks): Calculate the minimum volume of 4.20 mol dm–3 hydrochloric acid required to react with 0.100 mol of magnesium. Give your answer in cm3 and to an appropriate num
June 2025, AS Component 1, Q10(b)(ii) (1 mark): Name the piece of apparatus most suitable for measuring this volume of solution. [1]
June 2025, AS Component 1, Q10(b)(iii) (1 mark): Calculate the number of hydrogen ions present in this volume. [1] Number of hydrogen ions =
June 2025, AS Component 1, Q10(c) (2 marks): Calculate the minimum mass of magnesium required to produce 30.0 cm3 of hydrogen gas measured at 25 °C. Assume an excess of hydrochloric acid is used. [2] Mass
June 2025, AS Component 1, Q13(a)(iii) (3 marks): Calculate the volume of oxygen that would be produced by the complete decomposition of 1.35 g of potassium chlorate at 650 K and a pressure of 1 atm. [3] Volu
June 2025, AS Component 1, Q13(a)(iv) (1 mark): Suggest how you would prove that complete decomposition had been achieved. [1]
June 2025, AS Component 2, Q6 (2 marks): Calculate the number of molecules in 25.6 kg of ethanoic acid (Mr 60.0). [2] Molecules of ethanoic acid =
June 2025, AS Component 2, Q7(b) (3 marks): When 6.26 g of 1-bromobutane (Mr 137) was converted into pentanenitrile, C4H9CN, 2.58 g of the product was obtained. Calculate the percentage yield for this rea
June 2025, AS Component 2, Q8(a) (9 marks): Use all the information to identify compound X. [9]
June 2025, AS Component 2, Q11(b)(i) (4 marks): Show that the technician is correct. [4]
June 2024, Component 1, Q5 (2 marks): 10.0 g of magnesium hydroxide is heated until it undergoes thermal decomposition. Calculate the maximum mass of magnesium oxide that can be formed in this react
June 2024, Component 1, Q6 (2 marks): Interhalogen compounds contain two types of halogen atom only. In a mass spectrum the molecular ion of one interhalogen compound appears as two peaks, one at m/
June 2024, Component 1, Q10(b)(ii) (3 marks): Naturally-occurring samples of actinium usually consist of mixtures of 227Ac and 228Ac. One sample has a relative atomic mass of 227.12. Calculate the percentag
June 2024, Component 1, Q12(a) (3 marks): Calculate the value of c. You must show your working. [3] c =
June 2024, Component 1, Q12(d) (2 marks): Find the value of a. Use this and your answers to parts (a) and (c) to give the formula of chukanovite. [2] Formula
June 2024, Component 1, Q15(d)(ii) (3 marks): XeF2 is soluble in anhydrous HF with a solubility of 162 g per 100 g of HF at 20 °C. The density of anhydrous HF is 1.66 g cm–3 Calculate the solubility of XeF2
June 2024, Component 2, Q5(a) (2 marks): Find the relative molecular mass of the acid. [2] Mr =
June 2024, Component 2, Q5(b) (2 marks): Use your answer to (a) to find the relative molecular mass of the R group and hence the formula of the alcohol. [2]
June 2024, Component 2, Q6(c) (1 mark): The solubility of phenylalanine at two temperatures is shown in the table. Temperature / °C Solubility / g per 100 g of water 25 1.41 100 6.89 A saturated solut
June 2024, Component 2, Q6(d) (2 marks): Amino acids produce nitrogen gas when reacted with nitric(III) acid. 3.40 g of a damp sample of phenylalanine (Mr 165) was dissolved in water and reacted with n
June 2024, Component 2, Q7(d)(i) (1 mark): In an experiment 0.5 cm3 of a 1.0 mol dm–3 bromine solution was used. The bromine acts as a catalyst in this reaction. Calculate the number of moles of bromine
June 2024, Component 2, Q8(d)(iii) (3 marks): Calculate the percentage yield of phenyloxirane. [3] Percentage yield = %
June 2024, Component 2, Q9(d)(i) (1 mark): Chemical analysis of compound T showed that it contains 85.7% of carbon and 14.3% of hydrogen by mass. Explain why this is not helpful in finding the structure
June 2024, Component 2, Q9(d)(v) (1 mark): At 426 K and 1 atm, 4.90 g of compound T has a volume of 1.75 dm3 The molar gas volume under these conditions is 35.0 dm3. Use this information to show that the
June 2024, Component 2, Q10(d)(ii) (2 marks): Use your equation in part (i) above to calculate the increase in gas volume, measured in dm3, that occurs when 1 mol of solid CH2CH(ONO2) reacts with oxygen. Yo
June 2024, Component 2, Q11(a)(iii) (2 marks): In an experiment 6.7 g of prop-2-enal was obtained from 0.30 mol of the trihydric alcohol. Calculate the percentage yield of prop-2-enal. Give your answer to an
June 2024, Component 2, Q11(a)(iv) (1 mark): Calculate the atom economy of this reaction. [1] Atom economy = %
June 2024, Component 2, Q12(a) (6 marks): You are provided with a sample of a diamide, where R is an alkyl group. O O C R C H2N NH2 6.32 g of the diamide reacts with aqueous sodium hydroxide to produce
June 2024, Component 2, Q12(c)(i) (1 mark): 0.800 g of ethanoic acid was dissolved in 150 g of benzene. The resulting solution froze at a temperature 0.222 K lower than that of pure benzene. Use the equat
June 2024, Component 3, Q4(c)(i) (2 marks): Show that an excess of ethanoic anhydride was present in the reaction mixture. [2] density of ethanoic anhydride = 1.08 g cm–3
June 2024, Component 3, Q4(c)(ii) (2 marks): Calculate the overall percentage yield of this two-stage reaction. [2] Percentage yield = %
June 2024, Component 3, Q4(d)(iv) (5 marks): Nitric(III) acid (nitrous acid), HNO2, is an unstable compound and is made when required by the reaction of a dilute acid, for example HCl, with sodium nitrate(
June 2024, Component 3, Q5 (12 marks): Tutton’s salts are a family of double salts with the formula AwBx(SO4)y.z(H2O). They contain two different cations, Aa+ and Bb+. The following tests were carrie
June 2024, AS Component 1, Q1 (1 mark): Silver chloride can be precipitated by the following reaction. AgNO3(aq) + NaCI(aq) AgCI(s) + NaNO3(aq) Mr 170 Mr 58.5 Mr 143.5 Mr 85 Calculate the atom economy
June 2024, AS Component 1, Q4 (2 marks): Calcium hydroxide decomposes on heating as shown below. Ca(OH)2(s) CaO(s) + H2O(g) Calculate the maximum mass of calcium oxide that can be produced when 75.0 g
June 2024, AS Component 1, Q6(d)(i) (1 mark): Give the meaning of the term relative isotopic mass. [1]
June 2024, AS Component 1, Q8(b)(i) (3 marks): Calculate the number of gold atoms present in a square of pure gold leaf that is 3.0 cm × 3.0 cm and 0.1 μm thick. [3] Number of atoms =
June 2024, AS Component 1, Q8(b)(ii) (2 marks): Pure gold is 24-karat but the most commonly used gold is 22-karat yellow gold. Calculate the number of moles of gold in a 1.0 cm cube of 22-karat yellow gold. [
June 2024, AS Component 1, Q9(b)(i) (3 marks): The reaction did not go to completion. I. Calculate the maximum possible number of moles of carbon dioxide that could be produced. [1] Moles of carbon dioxide =
June 2024, AS Component 1, Q9(b)(ii) (2 marks): Describe and explain how the yield of calcium oxide can be maximised. [2]
June 2024, AS Component 1, Q9(c) (4 marks): Calculate the volume occupied by 3.75 × 10–3 mol of carbon dioxide at a temperature of 800°C and 2 atm pressure. Give your answer in cm3. [4] Volume = cm3
June 2024, AS Component 1, Q10(a) (4 marks): A student wanted to make a solution of magnesium sulfate. Give a description, including quantities, of how she could make 250 cm3 of an aqueous solution of 1.00
June 2024, AS Component 1, Q11(d) (2 marks): The concentration of bromide ions in seawater from the Dead Sea can be as high as 12 g dm–3. Calculate the maximum number of moles of bromine that can be extrac
June 2024, AS Component 2, Q6 (2 marks): Propanoic acid reacts with metals such as magnesium to produce hydrogen. Mg + 2C2H5COOH (C2H5COO)2Mg + H2 Calculate the minimum mass of magnesium needed to comp
June 2024, AS Component 2, Q7(c) (3 marks): A compound contains 24.1% carbon, 4.10% hydrogen and 71.8% chlorine by mass. Its mass spectrum is shown below. Intensity 98 102 0 20 40 60 80 100 m / z Calculat
June 2024, AS Component 2, Q8(a)(iv) (3 marks): A mass of 0.564 g of compound B reacts in a 1:1 ratio with hot aqueous potassium hydroxide. The residual solution is treated with dilute nitric acid followed by
June 2024, AS Component 2, Q10(b) (4 marks): In another preparation of ethanoic acid from ethanol, 8.23 g of ethanoic acid was obtained. The percentage yield of ethanoic acid was 80%. Calculate the volume
June 2024, AS Component 2, Q11(g) (2 marks): Calculate the actual mass of zinc needed to react with the copper(II) sulfate solution. [2] Mass = g
Autumn 2021, Component 1, Q9(b) (2 marks): Caesium is extracted from the mineral pollucite. A sample of pollucite contains 24.16 % caesium by mass, with each formula unit containing one caesium ion. Find
Autumn 2021, Component 1, Q10(d)(ii) (2 marks): Calculate the mass of calcium propanoate formed by addition of 1.20 g of calcium oxide to excess propanoic acid. [2] Mass = g
Autumn 2021, Component 1, Q13(b) (4 marks): Aluminium chloride dimers can break up in the gas phase to form AlCl3 molecules. The mass spectrum of these molecules contains several molecular ion peaks with
Autumn 2021, Component 1, Q13(c)(ii) (5 marks): The volume of 1.000 kg of liquid water was measured at a range of temperatures. The results are shown in the graph. 1.005 1.004 1.003 1.002 1.001 1.000 0.999 0
Autumn 2021, Component 1, Q14(c)(ii) (4 marks): Limestone is a common rock which consists mainly of calcium carbonate, but often contains dolomite [CaMg(CO3)2] as well as insoluble, inert impurities such as s
Autumn 2021, Component 1, Q14(c)(iii) (2 marks): Limestone is a common rock which consists mainly of calcium carbonate, but often contains dolomite [CaMg(CO3)2] as well as insoluble, inert impurities such as s
Autumn 2021, Component 1, Q14(d)(i) (2 marks): Limestone is a common rock which consists mainly of calcium carbonate, but often contains dolomite [CaMg(CO3)2] as well as insoluble, inert impurities such as s
Autumn 2021, Component 1, Q15(a) (2 marks): The concentration of all four solutions was 0.10 mol dm–3, however the solutions were labelled with concentrations in g dm–3. Complete the table by finding the
Autumn 2021, Component 2, Q1(a) (1 mark): State the empirical formula of methylcyclohexane. [1]
Autumn 2021, Component 2, Q2(a) (2 marks): Bromine is very hazardous and the quantity required is usually measured by volume. The density of bromine is 3.16 g cm–3. Calculate the volume of bromine needed
Autumn 2021, Component 2, Q4 (2 marks): 0.774 g of the silver salt of an organic acid was heated and produced gaseous products and 0.365 g of solid silver. O Ag + gaseous products R C O–Ag+ Use this i
Autumn 2021, Component 2, Q6(b)(i) (3 marks): In an experiment, 8.38 g of an impure sample of calcium propanoate reacted with an excess of aqueous sulfuric acid, giving 5.70 g of calcium sulfate (Mr 136). C
Autumn 2021, Component 2, Q6(c) (2 marks): At 0 °C the solubility of calcium propanoate in water is 49 g / 100 g of water. This rises to 56 g / 100 g of water at 100 °C. Calculate the mass of calcium pro
Autumn 2021, Component 2, Q7(b)(i) (3 marks): 6-Aminohexanoic acid is not readily available and Nylon-6 is made in industry by a series of reactions starting with cyclohexane, which is first converted to cy
Autumn 2021, Component 2, Q7(d)(iv) (1 mark): In the experiment 0.20 mol of cyclohexanol was dehydrated using sulfuric acid. After purification 10 cm3 of cyclohexene was obtained. Calculate the percentage y
Autumn 2021, Component 2, Q7(e)(i) (2 marks): 6.86 g of liquid L reacted with 0.070 mol of bromine (Br2) to give a new compound of formula C6H10OBr2 Use these quantities to show that this information fits b
Autumn 2021, Component 2, Q9(a)(i) (2 marks): Traditionally, thymol has been extracted from a number of plants, including the oil obtained from the herb thyme. The solvent used for this extraction is ethano
Autumn 2021, Component 2, Q9(b)(iv) (4 marks): Study the reaction sequence below and answer the questions that follow. H CH2 C CH2 Br Stage 1 reagent S H CH2 C CH2 CN Stage 2 H CH2 C CH2 CH2 NH2 compound T (
Autumn 2021, Component 2, Q10(a)(i) (2 marks): It can be made by reacting aqueous solutions of methanal and ammonia. 6CH2O + 4NH3 (CH2)6N4 + 6H2O hexamine Calculate the atom economy of this reaction to make
Autumn 2021, Component 2, Q10(c)(i) (2 marks): Calculate the percentage of chlorine in this mixture. [2] Percentage = %
Autumn 2021, Component 2, Q10(c)(ii) (1 mark): Use the graph to find the percentages of chloroethanoic acid and dichloroethanoic acid present in the mixture. [1] 56 54 52 50 48 Percentage 46 of chlorine 44
Autumn 2021, Component 2, Q11(b) (2 marks): 1,4-Dimethylbenzene (Mr 106) reacts with chlorine in a radical reaction to give 1,4-di(chloromethyl)benzene (Mr 175). H3C CH3(I) + 2Cl2(g) ClH2C CH2Cl(l) + 2HCl
Autumn 2021, Component 3, Q2(d) (4 marks): After purification, 2.9 g of pure phenyl benzoate was isolated. Show which of the reactants is in excess and hence calculate the percentage yield of this reacti
Autumn 2021, Component 3, Q4(a)(i) (3 marks): Outline an experimental procedure that she could carry out to find the value of x. [3]
Autumn 2021, Component 3, Q4(a)(ii) (2 marks): Having used a suitable experimental procedure, the student calculated that x = 2 and that the formula of the hydrated calcium sulfate is therefore CaSO4.2H2O. S
Autumn 2021, Component 3, Q4(b) (3 marks): An experiment was carried out to identify the element M in the salt M2SO4. A 1.59 g sample of the pure compound M2SO4 was dissolved in water and treated with an
Autumn 2021, Component 3, Q5(f)(ii) (3 marks): 0.123 dm3 of oxygen gas was produced on heating a sample of pure lead(IV) oxide. Calculate the mass of
Autumn 2020, Component 1, Q9(b)(i) (2 marks): Calculate the atom economy for this method of producing methyllithium. [2] Atom economy = ……… ………………… %
Autumn 2020, Component 1, Q9(d)(i) (3 marks): Use the volume of gas produced to calculate the concentration of the initial methyllithium solution. Give your answer to an appropriate number of significant fi
Autumn 2020, Component 1, Q9(d)(iii) (2 marks): State which of these two methods gives the more accurate value. Give a reason for your answer. [2]
Autumn 2020, Component 1, Q11(b)(i) (4 marks): Electrolysis was undertaken on 250 cm3 of a solution of sodium chloride of concentration 5.00 mol dm–3 until 2856 cm3 of hydrogen gas was produced at a temperat
Autumn 2020, Component 1, Q11(b)(ii) (2 marks): The chlorine gas produced in the reaction was stored under a pressure of 5.05 × 105 Pa at a temperature of 283 K. Calculate the volume of the chlorine gas under
Autumn 2020, Component 1, Q13(c) (3 marks): Concentrated aqueous ammonia solution at 298 K contains 31.0 % ammonia by mass. The density of this solution is 0.900 g cm–3. Calculate the concentration of thi
Autumn 2020, Component 2, Q4(a) (1 mark): Give the empirical formula of benzene-1,2,3-triol. [1]
Autumn 2020, Component 2, Q4(b)(i) (1 mark): Use the information given to calculate the value x in cm3. [1] x = cm3
Autumn 2020, Component 2, Q4(b)(ii) (2 marks): After removal of oxygen the remaining gas was passed through a gas chromatograph and gave the following result, where the figures are relative peak areas. 7 2 U
Autumn 2020, Component 2, Q6(a)(v) (2 marks): In the body, tyrosine is converted by enzymes into tyramine. One equation for this reaction is as follows. NH2 NH2 + CO2 COOH HO HO tyrosine tyramine Mr 181 Cal
Autumn 2020, Component 2, Q7(a) (5 marks): A sample of LPG has a mass of 10.48 g. It contains 3.52 g of propane with the rest being butane. The sample was completely burned, giving only carbon dioxide an
Autumn 2020, Component 2, Q7(b) (3 marks): In practice LPG contains small quantities of other materials including ethanethiol, C2H5SH (Mr 62). This is added to LPG so that any escape is detectable by its
Autumn 2020, Component 2, Q8(b)(i) (4 marks): 4.78 dm3 of hydrogen measured at 298 K and 1 atm pressure was needed to fully hydrogenate a certain mass of lycopene. Calculate the mass of lycopene used. [4] M
Autumn 2020, Component 2, Q8(b)(iii) (3 marks): The amount of lycopene present in tomatoes can be found by colorimetry. The absorption values of a number of standard solutions are measured and their values us
Autumn 2020, Component 2, Q11(a)(i) (2 marks): Calculate the mass of phenyl benzoate produced. [2] Mass = g
Autumn 2020, Component 2, Q11(a)(ii) (4 marks): Calculate the total volume of carbon dioxide produced measured at 298 K and 1 atm pressure, assuming that the di(benzoyl) peroxide decomposed by the two routes
Autumn 2020, Component 2, Q11(b) (6 marks): Liquid G contains only carbon, hydrogen and oxygen. The infrared spectrum of G showed no peaks at 1620–1670 cm–1, 1650–1750 cm–1 or 3200–3550 cm–1 The 13C NMR s
Autumn 2020, Component 3, Q2(d)(iii) (1 mark): Calculate the mass of barium carbonate obtained on heating the precipitate to constant mass. [1] Mass = g
Autumn 2020, AS Component 1, Q5 (2 marks): Water gas is a mixture of carbon monoxide and hydrogen that is made by passing steam over heated carbon. H2O(g) + C(s) H2(g) + CO(g) Calculate the atom economy
Autumn 2020, AS Component 1, Q9(b) (4 marks): Calculate the volume of nitrogen produced by the reaction of 20.0 cm3 of liquid hydrazine with excess oxygen. Assume that all measurements are taken at 273 K an
Autumn 2020, AS Component 1, Q11(c) (3 marks): The molecular ion peaks are at m/z 158, 160 and 162 in the mass spectrum of bromine, Br2. The areas of these peaks are in the ratio of 1 : 2 : 1. [3]
Autumn 2020, AS Component 1, Q12(a) (5 marks): Calculate the mass of hydrated barium chloride and the mass of residue. Hence determine the value of x. [5] x =
Autumn 2020, AS Component 1, Q12(b)(i) (1 mark): Suggest why the crucible was heated initially with the lid in place. [1]
Autumn 2020, AS Component 1, Q12(b)(ii) (1 mark): Suggest why the lid was placed on the crucible when it was left to cool. [1]
Autumn 2020, AS Component 1, Q12(c)(i) (1 mark): When this experiment is carried out the value of x obtained is often less than the theoretical value. Suggest a reason for this, assuming that the compound cont
Autumn 2020, AS Component 1, Q12(c)(ii) (1 mark): State an improvement that could be made to the practical procedure to overcome the problem you have identified in (c)(i). [1]
Autumn 2020, AS Component 1, Q12(d) (1 mark): If the error in each balance reading is ± 0.05 g, calculate the percentage error in the mass of hydrated barium chloride used in the experiment. [1] Percentage
Autumn 2020, AS Component 1, Q12(e) (1 mark): Apart from the improvement you identified in (c)(ii), suggest another change that could be made to improve the accuracy of the experiment. [1]
Autumn 2020, AS Component 1, Q13(a) (5 marks): A compound of carbon, hydrogen and oxygen contains 40.0 % carbon and 6.7 % hydrogen by mass. 1.52 g of the gaseous compound has a volume of 1.76 dm3 at a temper
Autumn 2020, AS Component 2, Q2(a) (1 mark): State the empirical formula of myrcene. [1]
Autumn 2020, AS Component 2, Q6 (2 marks): Collagen has the formula C57H91N19O16. Analysis of a sample showed that it contained 0.0204 mol of carbon. Calculate the simplest ratio of carbon atoms to nitro
Autumn 2020, AS Component 2, Q7(c) (2 marks): Ethanol is the main alcohol present in alcoholic drinks. When driving in England, the legal limit for alcohol in the blood is 80 mg per 100 cm3 of blood. Calcul
Autumn 2020, AS Component 2, Q7(d) (3 marks): A fluorocarbon has a relative molecular mass which is twice that of its empirical formula. 9.56 g of this compound contains 6.73 g of fluorine. Find its molecul
Autumn 2020, AS Component 2, Q8(b) (3 marks): Another student wanted to make 1-chloropentane. She started with pentan-1-ol and obtained 1.62 g of 1-chloropentane. The percentage yield of 1-chloropentane was
Autumn 2020, AS Component 2, Q10(b) (3 marks): The graph below shows the maximum temperature rise as different masses of zinc react with separate samples of 50.0 cm3 of 0.100 mol dm–3 hydrochloric acid. X Ma
June 2019, Component 1, Q2 (1 mark): Complete the definition below. Relative atomic mass is the average mass of an atom of an element compared to . [1]
June 2019, Component 1, Q7 (2 marks): A sample of the element boron contains 22.10 % boron-10 and 77.90 % boron-11. Calculate the relative atomic mass of this sample, giving your answer to four sign
June 2019, Component 1, Q9(b)(ii) (3 marks): The NaHSO4 formed in this preparation is hydrated and has the formula NaHSO4.xH2O. In an experiment a sample of NaHSO4.xH2O was heated to constant mass. The sam
June 2019, Component 1, Q10(b) (3 marks): In step 2 a white precipitate of mass 0.0672 g was produced. State which ion this step identifies and calculate the number of moles of this ion present in the o
June 2019, Component 1, Q10(f) (3 marks): Deduce the formula of atacamite. [3] Formula of atacamite
June 2019, Component 1, Q11(d) (2 marks): Selenium dioxide, SeO2, is a foul smelling solid, with a smell resembling rotting horseradish. It can be used to oxidise alkenes. SeO2 + C3H6 + H2O H2SeO2 + C3H
June 2019, Component 1, Q12(c) (3 marks): Chlorine can be used to produce bromine from the bromide ions present in seawater. An excess of chlorine is usually used in this process. In one experiment, a v
June 2019, Component 1, Q12(d)(i) (2 marks): Explain how ions are formed and separated in the mass spectrometer. [2]
June 2019, Component 1, Q12(d)(ii) (4 marks): The diagram below shows part of the mass spectrum of a chlorine-containing compound. There are no other significant peaks near this group of peaks and adjacent
June 2019, Component 2, Q1(c) (1 mark): Give the empirical formula of compound X. [1]
June 2019, Component 2, Q7(a) (2 marks): Calculate the atom economy of this reaction. [2] Atom economy = ……… %
June 2019, Component 2, Q7(b) (1 mark): There have been a number of instances of the illegal addition of melamine to baby milk. This addition appears to increase the percentage of protein in the milk,
June 2019, Component 2, Q8(c) (4 marks): Methane clathrate is the name given to methane trapped inside ice crystals. The permafrost contains extensive quantities of this material and there are worries
June 2019, Component 2, Q9(b) (4 marks): Compound L is an aromatic compound of formula C8H8Br2 (Mr 264). A sample of compound L of mass 3.22 g was refluxed with excess aqueous sodium hydroxide and the
June 2019, Component 2, Q10(b)(ii) (3 marks): N-ethanoylcysteine is used to treat an overdose of paracetamol. It can be produced by the reaction of cysteine with ethanoic anhydride. NH2 HS CH2 C COOH + (CH3
June 2019, Component 2, Q11(b)(i) (4 marks): 4.31 dm3 of hydrogen, measured at 312 K and at a pressure of 1.01 × 105 Pa, was needed to completely react with 8.29 g of ectocarpene to produce compound G. H3C
June 2019, Component 2, Q11(b)(ii) (2 marks): Find the molecular formula of ectocarpene and deduce the structural formula of an aromatic compound that has the same molecular formula as ectocarpene. [2] Mole
June 2019, Component 2, Q12(b)(iv) (2 marks): The mixture at the end of the reaction contains the two alkenes and a small quantity of unreacted 2-methylbutan-2-ol. A student found that 2-methylbutan-2-ol re
June 2019, Component 2, Q13(a) (4 marks): Diacetin is an ester of propane-1,2,3-triol that is used by some plants to attract bees. It reacts with aqueous sodium hydroxide to produce propane-1,2,3-triol
June 2019, Component 3, Q3(c)(i) (2 marks): The student was asked to prepare a 0.0200 mol dm–3 standard solution of potassium dichromate(VI), K2Cr2O7. Calculate the mass of potassium dichromate(VI) needed
June 2019, Component 3, Q4 (6 marks): A solid waste sample is known to contain only sodium carbonate, sodium nitrate and sodium sulfate. Outline an experimental procedure to show that • the sample c
June 2019, AS Component 1, Q8(b)(i) (6 marks): The relative atomic mass of a sample of an element can be found using a mass spectrometer. The diagram shows the main parts of a mass spectrometer. detector Use
June 2019, AS Component 1, Q8(b)(ii) (2 marks): The mass spectrum of an element T is shown. Use this to calculate the relative atomic mass, Ar , of the sample of T. [2] Relative abundance 5 10 15 20 25 m/z Ar
June 2019, AS Component 1, Q8(b)(iii) (1 mark): The mass spectrum includes a very small peak at m/z 10 (not visible above). Suggest which particle is responsible for the presence of this peak. [1]
June 2019, AS Component 1, Q9(c)(i) (1 mark): What is meant by the Avogadro constant? [1]
June 2019, AS Component 1, Q9(c)(ii) (3 marks): Calculate the number of oxygen atoms in 34.23 g of aluminium sulfate, Al2(SO4)3 Show clearly how you carried out the calculation. [3] Number of oxygen atoms =
June 2019, AS Component 1, Q11(c) (2 marks): Magnesium reacts with hydrochloric acid. Mg(s) + 2HCl(aq) MgCl2(aq) + H2(g) A sample of magnesium of mass 5.00 g was reacted with excess hydrochloric acid. 4.31
June 2019, AS Component 1, Q12(a)(ii) (3 marks): Calculate the maximum volume of gas, measured at 600 K and 1 atm pressure, that can be made by heating 88.0 g of NaClO3 Give your answer to an appropriate numbe
June 2019, AS Component 1, Q12(b) (2 marks): The active component of bleach is sodium chlorate(I), NaClO. This is prepared by passing chlorine into aqueous sodium hydroxide. 2NaOH(aq) + Cl2(g) NaClO(aq) +
June 2019, AS Component 1, Q12(c) (2 marks): Another compound containing sodium, chlorine and oxygen has the following composition by mass. Na 18.8 % Cl 29.0 % O 52.2 % Calculate its empirical formula. [2]
June 2019, AS Component 2, Q9(b) (2 marks): A concentration of “3 % w/v” means that there are 3 g of hydrogen peroxide in 100 cm3 of solution. Calculate the concentration of the aqueous hydrogen peroxide
June 2019, AS Component 2, Q11 (10 marks): Compound A contains 55.8 % carbon, 7.00 % hydrogen and 37.2 % oxygen by mass. Part of its infrared spectrum is shown below. 3000 2000 1500 1000 500 Wavenumber /
June 2019, AS Component 2, Q12(d) (2 marks): Calculate the mass of the magnesium strip used in the experiment. [2] Mass = g
June 2018, Component 1, Q10(a)(ii) (3 marks): This industrial process has a yield of 95.0 %. Calculate the mass of ethanal, in kg, that would be produced from 2.00 tonnes of ethene. [3] Mass of ethanal = kg
June 2018, Component 1, Q13(b) (4 marks): An alternative method is gravimetric analysis. Another sample of alloy is dissolved in concentrated nitric acid. The solution is neutralised and aqueous sodium
June 2018, Component 1, Q13(c) (2 marks): A student suggests that the alloys in parts (a) and (b) are the same. State and explain whether the evidence supports this statement and suggest what further ev
June 2018, Component 1, Q14(b)(i) (2 marks): A student says that this shows that the concentration of calcium ions in a saturated solution of calcium chloride is the same for solutions formed by dissolving
June 2018, Component 1, Q15(b)(i) (4 marks): When used in an oxy-acetylene torch the ethyne is released at a pressure of 135 kPa at 20 °C. Find the number of moles of ethyne in 1 cm3 and hence calculate th
June 2018, Component 1, Q15(b)(ii) (2 marks): The density of dry air at 0 °C and 135 kPa is 1.27 × 10–3 g cm–3. A student says that this shows that a vessel of negligible mass filled with ethyne will float
June 2018, Component 2, Q9 (1 mark): Draw the structure of a compound that has an empirical formula CH4N. [1]
June 2018, Component 2, Q10(c) (3 marks): Ethanol can be made from glucose by fermentation. C6H12O6(aq) 2C2H5OH(aq) + 2CO2(g) In an experiment 0.200 mol of glucose was dissolved in water and fermented u
June 2018, Component 2, Q10(d)(iii) (1 mark): The proportion of products present was found using HPLC. Calculate the percentage of compound A oxidised after 15 minutes. [1] Concentration / mol dm–3 Compound
June 2018, Component 2, Q14(a)(ii) (3 marks): Benzene is an example of an aromatic compound. There are a number of other aromatic systems. One of these is pyrrole. I. Pyrrole can be made by reacting butan-1
June 2018, Component 2, Q14(b)(i) (2 marks): In the first stage of a synthesis of DEPA, methylbenzene [Mr 92.1] reacts with chlorine until the increase in mass indicates that (chloromethyl)benzene, C6H5CH2
June 2018, Component 2, Q14(b)(iii) (1 mark): The overall yield of phenylethanoic acid, starting from methylbenzene, was 65 %. Calculate the mass of phenylethanoic acid [Mr 136] formed from 0.430 mol of met
June 2018, Component 2, Q15(a)(ii) (2 marks): 6.35 g of the dichloro compound formed from ketone W contained 50.3 % of chlorine by mass, the remainder being carbon and hydrogen. Calculate the relative molec
June 2018, Component 2, Q15(b)(i) (2 marks): In an experiment the following results were obtained. Mass of liquid L = 0.222 g Volume of vapour produced = 111 cm3 Temperature = 423 K Pressure = 9.50 × 104 P
June 2018, Component 3, Q2(d) (3 marks): Butan-1-ol can also be prepared directly from 1-aminobutane by reaction with nitric(III) acid (HNO2). Butan-1-ol is only one of many organic products formed, in
June 2018, Component 3, Q2(e)(iii) (3 marks): Assuming the decomposition of the benzenediazonium chloride is complete, calculate the total volume of nitrogen gas that would be formed at the end of the react
June 2018, AS Component 1, Q4 (2 marks): Using the formula of calcium sulfate, calculate the number of oxygen atoms present in 0.1 mol of calcium sulfate. [2] Number of oxygen atoms =
June 2018, AS Component 1, Q7 (2 marks): Ethanol, C2H5OH, can be made by the fermentation of glucose, C6H12O6. C6H12O6 2C2H5OH + 2CO2 Calculate the atom economy of this reaction. [2] Atom economy = %
June 2018, AS Component 1, Q8(b) (3 marks): The mass spectrum of naturally-occurring chlorine, Cl2, contains three lines of different heights in the molecular ion region. [3]
June 2018, AS Component 1, Q10(b)(i) (3 marks): 4.52 g of cerrusite were investigated by the method outlined in part (a) and the following results were obtained. Mass / g Empty container 21.47 Container + lea
June 2018, AS Component 1, Q12(e) (4 marks): 2.94 g of ethanoic acid were mixed with 2.07 g of ethanol and allowed to react. 2.73 g of ethyl ethanoate were produced. Calculate the percentage yield of this
June 2018, AS Component 1, Q13(a) (2 marks): Suggest how the mass of carbon dioxide and the mass of water could be measured in this experiment. [2]
June 2018, AS Component 1, Q13(b) (3 marks): Find the percentage by mass of each element in X. [3] Percentage carbon = % Percentage hydrogen = % Percentage oxygen = %
June 2018, AS Component 1, Q13(c) (2 marks): Calculate the empirical formula of X. [2] Empirical formula
June 2018, AS Component 1, Q13(d) (4 marks): 9.20 g of X, measured at a pressure of 103 kPa and a temperature of 100 °C, had a volume of 6.02 × 103 cm3. Calculate the relative molecular mass, Mr , of X. [4
June 2018, AS Component 1, Q13(e) (1 mark): Use your answers to parts (c) and (d) to deduce the molecular formula of X. [1] Molecular formula
June 2018, AS Component 2, Q9(f)(ii) (3 marks): The student predicted that since this was a multi-step process the overall yield would be less than 70 %. In the process, 5.00 cm3 of 2-methylbutan-2-ol were us
June 2017, Component 1, Q7 (2 marks): Helium is an example of an ideal gas. Use the ideal gas equation to find the volume of 0.267 mol of helium at –30 °C and 1 atm. [2] Volume = m3
June 2017, Component 1, Q10(a)(i) (2 marks): The atom economy of the steam reforming reaction is 17.8 %. Calculate the atom economy of the water gas shift reaction (equation 2), giving your answer to an ap
June 2017, Component 1, Q12(e)(i) (3 marks): Calculate the mass of xenon-131 produced per minute from 1 cm3 of the solution. [3] Mass = g
June 2017, Component 1, Q15(a) (3 marks): A lithium ion battery can sustain a current over an extended period of time so that a total charge of 1.2 × 104 C has flowed. Calculate the mass of lithium that
June 2017, Component 1, Q15(b)(ii) (3 marks): Find the value of c, the number of phosphate ions present in the molecular formula. You must show your working. [3] c =
June 2017, Component 1, Q15(b)(iii) (2 marks): Find the value of a, the number of lithium ions present in the molecular formula. [2] a =
June 2017, Component 1, Q15(b)(iv) (2 marks): Identify the first row d-block element M, and the number of atoms of this present in the molecular formula, b, and hence write the molecular formula of the comp
June 2017, Component 2, Q3(a) (2 marks): Calculate the percentage by mass of nitrogen in urea. [2] Percentage = %
June 2017, Component 2, Q8(a)(ii) (2 marks): After 24 hours, the crystals of ethanedioic acid produced were filtered off, recrystallised and weighed. 18.0 g of ethanedioic acid dihydrate, (COOH)2.2H2O [Mr
June 2017, Component 2, Q8(d) (3 marks): Many vegetables contain ethanedioic acid or its salts. In an experiment 140 g of Brussels sprouts were treated to produce a solution containing ethanedioic acid
June 2017, Component 2, Q8(e) (1 mark): Group 2 salts of dicarboxylic acids undergo decarboxylation on heating. For example, strontium ethanedioate [Mr 176] produces strontium carbonate and carbon mon
June 2017, Component 2, Q9(c)(i) (3 marks): In an experiment 4.08 g of limonene just removed the colour from 9.58 g of bromine. Use this information to calculate the relative molecular mass of limonene. [
June 2017, Component 2, Q10(f) (6 marks): Compound J is a polyamide that is produced from two different monomers. This polyamide is hydrolysed by boiling it with aqueous sodium hydroxide. After acidifyi
June 2017, Component 2, Q12(a)(ii) (3 marks): The oxidation of 2-chloroethanol (Mr 80.6) produces chloroethanoic acid together with a little chloroethanal. H O ClCH2 C H ClCH2 C OH OH 5.80 g of chloroethano
June 2017, Component 3, Q2(b)(i) (3 marks): When 2.27 g of metal Y are added to 600 cm3 of water, the concentration of the metal hydroxide solution formed on complete reaction is 0.0431 mol dm−3. [3] Iden
June 2017, Component 3, Q4(b)(i) (2 marks): Calculate the total number of moles of bromine added in step 1. [2] n(Br2) added = mol
June 2017, AS Component 1, Q12(a)(i) (4 marks): Use the data to determine the value of x in the formula BaCl2.xH2O. You must show your working. [4] x =
June 2017, AS Component 1, Q12(a)(ii) (1 mark): Why did the instructions say that the lid should be in place when the heating was carried out? [1]
June 2017, AS Component 1, Q12(a)(iii) (4 marks): Ethan said that Caroline’s method was inaccurate, even though she had carried out the experiment carefully and recorded all her results correctly. Suggest two w
June 2017, AS Component 1, Q12(a)(iv) (1 mark): Caroline agreed that her experiment had been inaccurate but said that it gave the correct answer for x. Comment on why Caroline was correct and that accuracy ne
June 2017, AS Component 1, Q13(e) (1 mark): Calculate the relative formula mass of the carbonate and hence state whether the mineral is magnesite or dolomite. Assume that the mineral is a pure compound. [
June 2017, AS Component 1, Q13(g)(i) (3 marks): Use the ideal gas equation, pV = nRT, to calculate the number of moles of carbon dioxide formed. Show your working. [3] n(CO2) = mol
June 2017, AS Component 1, Q13(g)(ii) (1 mark): Show whether or not this extension confirms the conclusion reached in part (e). [1]
June 2017, AS Component 2, Q8(a)(iv) (2 marks): Ethanol has a density of 0.79 g cm−3 at room temperature. Calculate the number of moles of ethanol in 12.0 cm3 [2] n = mol
June 2017, AS Component 2, Q8(b) (3 marks): In another preparation of ethanoic acid from ethanol, 10.2 g of pure ethanoic acid were obtained. The percentage yield of ethanoic acid was 65 %. Calculate the
June 2017, AS Component 2, Q9(a)(i) (3 marks): Calculate both the empirical and molecular formulae of the compound. [3] Empirical formula Molecular formula
June 2017, AS Component 2, Q11(c) (2 marks): Elinor told Adam that in this experiment the carbonate needed to be in excess. He replied that it was. Is he correct? Justify your answer. [2]
June 2016, AS Component 1, Q5 (1 mark): What is meant by the Avogadro constant? [1]
June 2016, AS Component 1, Q7 (2 marks): Aspirin can be prepared by the reaction shown below. C6H4(OH)COOH + (CH3CO)2O C6H4(OCOCH3)COOH + CH3COOH aspirin Calculate the atom economy of this reaction. [2
June 2016, AS Component 1, Q9(a) (2 marks): Define relative atomic mass. [2]
June 2016, AS Component 1, Q9(b)(i) (1 mark): On the diagram label the magnet. [1]
June 2016, AS Component 1, Q9(b)(ii) (2 marks): Explain what is happening in the mass spectrometer in the region labelled A. [2]
June 2016, AS Component 1, Q9(c) (2 marks): The mass spectrum below was obtained from a sample of lithium. Use the spectrum to calculate the relative atomic mass for this sample of lithium. Give your answ
June 2016, AS Component 1, Q9(d) (3 marks): Bromine exists as two isotopes with mass numbers 79 and 81. In a sample of bromine, Br2, there are approximately the same amounts of each isotope. On the mass s
June 2016, AS Component 1, Q13(c)(iii) (2 marks): The mass of silver chloride obtained was 0.93 g. Calculate the percentage of silver in the ore. [2] Percentage = %
June 2016, AS Component 2, Q7(f) (5 marks): The mass spectrum of a CFC shows two major signals at m/z 135 and 137 in the ratio of 3:1 and molecular ion peaks at 170, 172 and 174. The CFC contains 14.0 % c
June 2016, AS Component 2, Q8(d) (2 marks): Calculate how much solid hydrated sodium thiosulfate, Na2S2O3.5H2O, Beverly used to make the original solution. [2] Mass = g
June 2016, AS Component 2, Q8(e) (2 marks): Describe how Beverly prepared the 0.120 mol dm−3 sodium thiosulfate solution that she used in experiment 3 from the original 0.200

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