Spectroscopy and chromatography: Edexcel International A Level Chemistry questions

Every Edexcel International A Level Chemistry exam question on 15E Spectroscopy and chromatography (specification points 15.17–15.23), 2019–2025, with its mark scheme and examiner’s report.

All 117 questions on Spectroscopy and chromatography, as a list

June 2025, Unit 4, Q7 (1 mark): High resolution mass spectrometers can give peak data accurate to four decimal places. An organic compound X has a molecular ion peak at m / z = 60.0210 . The a
June 2025, Unit 4, Q8 (1 mark): A thin layer chromatogram of a substance is shown. solvent front position of sample starting point What is the Rf value of the sample? A 0.27 B 0.69 C 0.73 D 1.
June 2025, Unit 4, Q16 (6 marks): *16 Proton NMR spectroscopy and mass spectrometry give detailed information about the structure of organic compounds. Discuss the similarities and differences i
June 2025, Unit 5, Q13(a) (1 mark): How many peaks are there in the (1) A one B two C three D five
June 2025, Unit 5, Q13(b) (1 mark): Four students sketched the high-resolution proton NMR spectrum of 2,3-dimethylbutane. Which sketch is most likely to be correct? (1) A B 2 1 0 2 1 0 C D 2 1 0 2
June 2025, Unit 5, Q17(c)(i) (2 marks): Briefly describe how trimethylamine will be separated from other chemicals present in the sample of air. (2)
June 2025, Unit 5, Q17(c)(ii) (1 mark): High-performance liquid chromatography (HPLC) is used to measure levels of trimethylamine and trimethylamine N-oxide in blood and urine. Label the x-axis on the
June 2025, Unit 5, Q17(c)(iii) (1 mark): Name the analytical technique that can be used with either GC or HPLC to identify the compound responsible for each peak. (1)
June 2025 (A), Unit 5, Q17(d)(ii) (3 marks): The high resolution proton NMR spectrum of methyl orange has several peaks, some of which are very close together. Predict the chemical shift and the relative i
June 2025 (A), Unit 5, Q19(a)(iii) (1 mark): Carbon‑13 NMR spectra usually have a peak at a chemical shift of 0. Identify the compound responsible for this peak. (1)
June 2025 (A), Unit 5, Q19(a)(iv) (3 marks): Complete the carbon‑13 NMR spectrum of alanine showing the chemical shift values for each peak and the carbon atoms responsible for the peaks. (3) 200 150 100 5
January 2025, Unit 4, Q17(a) (3 marks): There are four ester isomers with the molecular formula C4H8O2 . Their displayed formulae are shown. H H H O O H H H H C C H C C C H O C C O C H H H H H H H Est
January 2025, Unit 4, Q17(b)(i) (2 marks): The displayed formulae of two of these esters are shown. H H H H O H C H C H O C H C H H C C O C H H O C H C C H H H H H H H Ester X Ester W Esters W and X both
January 2025, Unit 4, Q17(b)(ii) (4 marks): The displayed formulae of two different esters are shown in the boxes. Label the displayed formulae of the two esters Y and Z to show the proton environments an
January 2025, Unit 4, Q17(b)(iii) (1 mark): Draw the displayed formula of the C5H10O2 ester which has only 2 peaks in its low-resolution proton NMR structure. (1)
January 2025, Unit 4, Q20(e)(i) (1 mark): High-performance liquid chromatography, HPLC, is used for analysis in the extraction process. The HPLC equipment is connected to a detector which records peaks
January 2025, Unit 5, Q16(b) (1 mark): Which compound does not have the same number of peaks in the low‑resolution proton NMR spectrum and in the 13C NMR spectrum? (1) A compound W B compound X C com
January 2025, Unit 5, Q17(b) (1 mark): In a high‑resolution proton NMR spectrum of asparagine, what would be the splitting pattern for the protons indicated by the arrow? O NH2 C CH2 H2N C COOH H (1)
October 2024, Unit 4, Q3(c) (1 mark): A sample containing 2 × 10–9 g cm–3 of nandrolone was analysed using gas chromatography. The chromatogram produced is shown. Absorption 0 1 2 3 4 5 6 7 8 9 Rete
October 2024, Unit 4, Q12 (1 mark): Which isomer has the most peaks in its 13C NMR spectrum? A B C D
October 2024, Unit 4, Q16(b)(i) (2 marks): Complete the labelling of this structure to show each of the other proton environments in X, clearly linking any that are the same. (2)
October 2024, Unit 4, Q16(b)(ii) (3 marks): Describe three ways in which the high resolution 1H NMR spectrum can be used to distinguish between the methyl groups in X, other than a. (3)
October 2024, Unit 4, Q16(c) (1 mark): An isomer of X is a carboxylic acid with five peaks in its 13C NMR spectrum. Draw a possible skeletal structure for this carboxylic acid. (1)
October 2024, Unit 5, Q19(e)(ii) (1 mark): Identify with an asterisk (*) the carbon atom environment in α-ionone which would be expected to produce a peak with a quartet splitting pattern in a high resol
October 2024, Unit 5, Q19(e)(iii) (1 mark): Predict the number of peaks in the carbon-13 NMR spectrum of β-ionone, which has the molecular formula C13H20O . Justify your answer. O β-ionone (1)
June 2024, Unit 4, Q13 (1 mark): Which compound has most peaks in its 13C NMR spectrum? A CH3COCH3 B CH3COCH2CH3 C CH3CH2COCH2CH3 D CH3COCH2CH2COCH3 Use this space for any rough working. Anythi
June 2024, Unit 4, Q14 (1 mark): The high resolution 1H NMR spectrum of an ester is shown. 9H 3H 2H 4 3 2 1 0 δ / ppm What is the skeletal formula of this ester? Use the Data Booklet as a sourc
June 2024, Unit 5, Q15(d)(i) (2 marks): Explain the relative intensities of the peaks at m / z values of 162, 164 and 166. (2)
June 2024, Unit 5, Q15(d)(ii) (1 mark): Suggest why there is a corresponding set of peaks at m / z values of 163, 165 and 167. (1)
June 2024, Unit 6, Q1(c)(ii) (1 mark): A low resolution proton NMR spectrum of A shows four peaks with relative areas of 1:2:2:1. Deduce which of the structures in (c)(i) is correct, by identifying t
January 2024, Unit 4, Q11(c) (1 mark): How many peaks would be expected to appear in a carbon‑13 (13C) NMR spectrum of carvone? (1) A 10 B 9 C 8 D 7
January 2024, Unit 4, Q18(d)(i) (2 marks): Label the displayed formula to show the protons responsible for these two peaks. (2) H H O H H C C C O C H H O H H
January 2024, Unit 4, Q18(d)(ii) (2 marks): Complete the table to show the expected number of hydrogen atoms and expected splitting pattern for peaks J and K. (2) Number of Splitting δ / ppm Peak hydrogen
January 2024, Unit 5, Q10(a) (1 mark): Which of the esters have five peaks in their 13C NMR spectrum? (1) A P only B Q and R only C R and S only D Q, R and S only
January 2024, Unit 5, Q10(b) (1 mark): Which of the esters will not have a doublet in its high resolution proton NMR spectrum? (1) A P B Q C R D S
January 2024, Unit 6, Q2(b)(ii) (2 marks): There are only two peaks in the 13C NMR spectrum of X. Draw the displayed formula of X, labelling the carbon environments. (2)
October 2023, Unit 4, Q12 (1 mark): Polymer waste may be disposed of by incineration. At a plant carrying out this process with poly(propene), a waste gas was produced that was thought to be eithe
October 2023, Unit 4, Q13(a) (1 mark): What is the Rf value for compound X? (1) A 0.33 B 0.38 C 0.60 D 0.62
October 2023, Unit 4, Q13(b) (1 mark): Y travelled further than X. How do the attractions between Y and X to the stationary and mobile phases compare? (1) Attraction between Y and the Attraction betw
October 2023, Unit 4, Q17(b)(i) (1 mark): State why it is not possible to distinguish any of these isomers from the number of peaks in their 13C NMR spectra. (1)
October 2023, Unit 4, Q17(b)(ii) (3 marks): Complete the table below to give the number of peaks in a low resolution 1H NMR spectrum of each isomer. (3) Name Skeletal formula Number of peaks O butanoic ac
October 2023, Unit 4, Q17(b)(iii) (1 mark): One of the 1H NMR spectra has a peak with a chemical shift, δ, greater than 10 ppm. Identify the isomer, and the proton environment responsible for this peak. (
October 2023, Unit 4, Q17(b)(iv) (2 marks): The high resolution 1H NMR spectrum of one of the isomers contains a multiplet of five peaks (a quintet). Explain, with reference to the structure of one of the
October 2023, Unit 5, Q21(e) (2 marks): The high resolution proton (1H) NMR spectra of acetylsalicylic acid and methyl salicylate both contain four peaks from the protons on the benzene ring and two o
June 2023, Unit 4, Q4(a) (1 mark): Which is correct for the labels on the axes? (1) x-axis y-axis A absorption time B Rf absorption C time Rf D time absorption
June 2023, Unit 4, Q4(b) (1 mark): Which is correct for the components E, F and G ? (1) Most attracted to Most abundant stationary phase A E E B G E C E F D G F
June 2023, Unit 4, Q19(a)(i) (3 marks): Complete the table for these three isomers. (3) Number of peaks in Isomer Skeletal formula 13C NMR spectrum 1 2 3
June 2023, Unit 4, Q19(a)(ii) (6 marks): The high resolution proton NMR spectrum of one of these isomers is shown. 5 4 3 2 1 0 Chemical shift, δ / ppm Deduce which isomer is present in the sample, expl
June 2023, Unit 4, Q22(a) (3 marks): Sketch the low resolution proton NMR spectrum of Tris (C4H11NO3). Use your Data Booklet. (3) 10 9 8 7 6 5 4 3 2 1 0 Chemical shift, δ / ppm
January 2023, Unit 4, Q16 (1 mark): The chromatogram of a substance X is shown. solvent front substance X baseline What is the Rf value for substance X? A 0.28 B 0.62 C 0.70 D 0.86
January 2023, Unit 4, Q18(b)(iii) (3 marks): A simplified high resolution proton NMR spectrum of X is shown. The numbers above the peaks are the relative peak areas. Note that the chemical shifts for X are
January 2023, Unit 4, Q18(b)(iv) (2 marks): A simplified carbon‑13 NMR spectrum of X is shown. 200 160 120 80 40 0 δ / ppm State what additional information about the structure of X is given by this spect
January 2023, Unit 4, Q18(b)(v) (1 mark): Draw the structure of X using the information from (b)(ii) to (b)(iv). (1)
January 2023, Unit 5, Q11(b) (1 mark): What are the expected splitting patterns in the high resolution proton NMR spectrum of valine for the protons shown in bold? (1) Splitting pattern for Splitting
October 2022, Unit 4, Q14 (1 mark): Which change decreases the retention time in gas chromatography? A decreasing the column temperature B increasing the carrier gas flow rate C decreasing the amo
October 2022, Unit 4, Q17(d) (6 marks): Sodium ethanoate, CH3COONa , reacts with 2-methylpropanoyl chloride, (CH3)2CHCOCl , to form organic compound Z and sodium chloride, NaCl . The molecular ion pea
October 2022, Unit 5, Q16 (1 mark): The structure of a hydrocarbon is shown. How many peaks will there be in the 13C NMR spectrum of this compound? A four B five C six D seven
October 2022, Unit 5, Q21(b)(i) (3 marks): Explain why only one of the two possible structural formulae of R can give these data. (3)
October 2022, Unit 5, Q21(b)(ii) (3 marks): In the high resolution proton NMR data for the R group in coniine, the peak for proton environment 2 is a sextet. Deduce the splitting patterns for proton envir
October 2022, Unit 6, Q3(e)(i) (2 marks): Explain the peaks in the NMR spectrum between 2.2 and 2.4 ppm. O CH3CH2CH2C OCH2CH3 ethyl butanoate (2)
October 2022, Unit 6, Q3(e)(ii) (3 marks): Predict how the high resolution proton NMR spectrum of ethyl propanoate will differ from that of ethyl butanoate in terms of the number of peaks and their split
June 2022, Unit 4, Q1(a) (1 mark): How many peaks are there in the low resolution proton NMR spectrum of 2‑methylpropan‑2‑ol? (1) A one B two C three D four
June 2022, Unit 4, Q1(b) (1 mark): Which compound has three peaks with relative peak areas of 3 : 2 : 1 in its low resolution proton NMR spectrum? (1) A propanal B propane C propan‑1‑ol D propan‑
June 2022, Unit 4, Q1(c) (1 mark): Which compound does not have a singlet peak in its high resolution proton NMR spectrum? (1) A butanoic acid B butanone C butanal D butan‑1‑ol Use this space for
June 2022, Unit 4, Q2 (1 mark): The high resolution mass spectrum of an organic compound X has a molecular ion peak with m / z = 58.0417 and another peak with m / z = 29.0390. Which compound i
June 2022, Unit 4, Q3 (1 mark): A high performance liquid chromatography (HPLC) system used a column with a non‑polar stationary phase and a solvent of methanol and water. A mixture of octane,
June 2022, Unit 4, Q4 (1 mark): A diagram of a thin layer chromatogram of substance Y is shown. solvent front position of substance Y baseline What is the Rf value of substance Y? A 0.25 B 0.6
June 2022, Unit 4, Q17(d)(i) (1 mark): Identify the chemical shift range and carbon environment of one peak you would expect to see in both spectra. (1) Chemical shift range Carbon environment
June 2022, Unit 4, Q17(d)(ii) (1 mark): State the number of peaks you would expect to see in each 13C NMR spectrum. (1) Propanal Propanone
June 2022, Unit 5, Q7(b) (1 mark): One of the monomers used to make PET is benzene-1,4-dicarboxylic acid. O O HO OH How many peaks are there in the 13C NMR spectrum of benzene‑1,4‑dicarboxylic ac
June 2022, Unit 6, Q2(c) (2 marks): The high resolution proton NMR spectrum of E is shown. P Q 11 10 9 8 7 6 5 4 3 2 1 0 δ / ppm The relative numbers of protons responsible for the singlet peaks s
January 2022, Unit 4, Q16 (1 mark): In gas chromatography, a gas containing a mixture is passed over a liquid stationary phase. The main reason a mixture is separated into its components is becaus
January 2022, Unit 4, Q17 (1 mark): In HPLC, the mobile and stationary phases are Mobile phase Stationary phase A gas liquid B gas solid C liquid gas D liquid solid
January 2022, Unit 4, Q20(b)(ii) (1 mark): State how you might use your answer to (b)(i) and a mass spectrum of compound A to prove that compound A is an isomer of hexanoic acid. (1)
January 2022, Unit 4, Q20(c) (2 marks): Compound B, another isomer with the molecular formula C6H12O2, contains a ring of six carbon atoms. The carbon‑13 NMR spectrum has only two peaks, one of which
January 2022, Unit 5, Q6(a) (1 mark): What is the number of peaks in the 13C NMR spectrum of methylbenzene? (1) A seven B six C five D four
January 2022, Unit 5, Q7 (1 mark): The mass spectrum of the compound shown is obtained using a high resolution mass spectrometer. O What is the mass to charge ratio, m / z, of the molecular ion o
January 2022, Unit 5, Q15(b) (7 marks): The high resolution proton NMR spectrum of Q is shown. Area under curve 5 2 2 3 10 9 8 7 6 5 4 3 2 1 0 δ (ppm) Deduce the structure of Q. Justify your answer by
January 2022, Unit 6, Q2(c) (2 marks): The high resolution proton NMR spectrum of X contains only two singlets with relative peak areas of 3 : 2. Draw the structure of X, identifying the two proton e
January 2022, Unit 6, Q2(d)(ii) (2 marks): The 13C NMR spectrum of Y contains four peaks. Give two possible structures for Y. (2) Structure 1 Structure 2
January 2022, Unit 6, Q2(d)(iii) (2 marks): Explain how the low resolution proton NMR spectrum of Y would confirm which of your structures in (d)(ii) is correct. Chemical shifts are not required. (2)
January 2022, Unit 6, Q2(e)(ii) (3 marks): The high resolution proton NMR spectrum of Z contains four peaks (J, K, L and M). Peak J has the highest chemical shift, showing that this proton environment is
October 2021, Unit 4, Q16(c) (5 marks): A simplified high resolution proton (1H) NMR spectrum of compound X is shown. 12 10 8 6 4 2 0 δ / ppm Explain how the number of peaks in the 1H NMR spectrum, to
October 2021, Unit 5, Q19(f)(ii) (2 marks): The 13C NMR spectrum of one of these arenes, compound X, is shown. two peaks very close in chemical shift 200 180 160 140 120 100 80 60 40 20 0 δ / ppm Identify
October 2021, Unit 6, Q4(f)(iii) (2 marks): The part of the 13C NMR spectrum of X corresponding to the R group contains only two peaks. Deduce the structure of X. (2)
June 2021, Unit 4, Q8(b) (1 mark): Which of the carbon atoms is responsible for a peak at 72 ppm in the 13C NMR spectrum of menthol? (1) A P B Q C R D S
June 2021, Unit 4, Q11(a) (1 mark): A spot caused by an amino acid has moved 42 mm from the baseline of a paper chromatogram. The Rf value for the amino acid under these conditions is 0.62. What i
June 2021, Unit 4, Q11(b) (1 mark): In gas chromatography, GC, which of these would be the most suitable carrier gas? (1) A argon B hydrogen C methane D oxygen Use this space for any rough working
June 2021, Unit 4, Q12 (1 mark): The high resolution mass spectrum of a compound X has a molecular ion peak at m / z = 44.0632. Accurate relative atomic masses are given in the table. Element R
June 2021, Unit 4, Q17(c)(i) (1 mark): Label the three remaining hydrogen environments B, C and D on the structure. (1) CH3 CH3 C O C H2 C C H2 CH3 H3C A O
June 2021, Unit 4, Q17(c)(ii) (3 marks): Complete the table. (3) Hydrogen Splitting pattern Relative environment of peak peak area A triplet 3 B C D
June 2021, Unit 5, Q15 (1 mark): How many peaks are there in the carbon-13 (13C) NMR spectrum of methylcyclohexane? methylcyclohexane A one B three C five D seven
June 2021, Unit 5, Q16 (1 mark): In the high resolution proton NMR spectrum of propan-2-ol, CH3CHOHCH3 there are A one singlet, one doublet and a heptet B one singlet, two doublets and a heptet
June 2021, Unit 5, Q19(c) (6 marks): A simplified high resolution proton NMR spectrum of Y is shown. The relative peak areas are given near each peak. 9 3 TMS 1 12.0 10.0 8.0 6.0 4.0 2.0 0.0 Chemic
June 2021, Unit 6, Q3(a)(i) (1 mark): the fewest peaks in its carbon-13 NMR spectrum. (1)
June 2021, Unit 6, Q3(a)(ii) (1 mark): the most peaks in its low resolution proton NMR spectrum. (1)
June 2021, Unit 6, Q3(a)(iii) (1 mark): three peaks with relative peak area 3:2:3 in its low resolution proton NMR spectrum. (1)
June 2021, Unit 6, Q3(a)(iv) (1 mark): one triplet and one quartet as the only peaks in its high resolution proton NMR spectrum. (1)
January 2021, Unit 4, Q16 (1 mark): A mixture of organic compounds was analysed using thin-layer chromatography. The Rf value was 0.92 for one of the components in the mixture. What can be deduced
January 2021, Unit 4, Q17(d)(i) (1 mark): The accurate relative atomic masses, Ar , of the three elements in E are shown in the table. Element Ar hydrogen 1.0078 carbon 12.0000 oxygen 15.9949 E contains
January 2021, Unit 4, Q17(d)(iv) (3 marks): Data from the high resolution proton NMR spectrum of E is shown. Chemical shift, į Peak Splitting pattern Relative peak area / ppm for TMS A 4.02 triplet 2 B 2.
January 2021, Unit 4, Q19(c)(iii) (2 marks): The carbon-13 (13C) NMR spectrum of F has four peaks. Identify F by drawing its displayed formula. Justify your answer by labelling the carbon atoms or groups o
January 2021, Unit 5, Q16 (1 mark): The structure of a hydrocarbon is shown. How many peaks will there be in the 13C NMR spectrum of this compound? A four B five C seven D eight Use this space for
January 2021, Unit 5, Q20(a)(i) (2 marks): Give the structures of the species responsible for these two peaks. (2)
January 2021, Unit 5, Q20(a)(ii) (1 mark): Give the structure of one other species that you would expect to produce a peak at a different m / z value in the mass spectrum of butanone. (1)
January 2021, Unit 5, Q24(d)(i) (1 mark): Identify the other proton environments of acetoin on the structure and label them B, C etc. (1)
January 2021, Unit 5, Q24(d)(ii) (2 marks): Complete the table to show the splitting pattern in the high resolution proton NMR spectrum of acetoin. (2) Proton environment Splitting pattern A
October 2020, Unit 4, Q17(a) (4 marks): Isomers A, B, C and D are structural isomers that all react with aqueous sodium carbonate to produce carbon dioxide. Isomer A is a straight-chain compound. Isom
October 2020, Unit 4, Q17(b)(i) (3 marks): Isomer E contains an ether functional group (R-O-R) and a ketone functional group. The low resolution proton NMR spectrum of isomer E has four peaks. The displa
October 2020, Unit 4, Q17(b)(ii) (1 mark): State the number of peaks in the carbon-13 (13C) NMR spectrum of E. (1)
October 2020, Unit 5, Q12 (1 mark): A compound with the formula C6H14 gives a 13C NMR spectrum with four peaks. Which compound gives this spectrum? A B C D
October 2020, Unit 6, Q2(b)(ii) (4 marks): A simplified high resolution proton NMR spectrum of Q is shown. The relative peak areas are given above each set of peaks. 6 1 TMS 1 12.0 10.0 8.0 6.0 4.0 2.0 0
January 2020, Unit 4, Q16(a)(i) (2 marks): Identify which groups of hydrogen atoms are responsible for each peak in the spectrum by adding the labels w, x, y and z to the appropriate parts of this displa
January 2020, Unit 4, Q16(a)(ii) (2 marks): Explain the splitting patterns of the peaks at 4.2 ppm and 1.3 ppm. (2)
January 2020, Unit 4, Q16(a)(iii) (1 mark): The carbon-13 (13C) NMR spectrum of ethyl 3-oxobutanoate has six peaks. Draw the structure of an isomer of ethyl 3-oxobutanoate that contains a carboxylic acid
January 2020, Unit 4, Q16(b)(i) (3 marks): Complete the diagram below, showing a chromatogram for ethyl 3-oxobutanoate, including appropriate labels. (3)
January 2020, Unit 4, Q16(b)(ii) (2 marks): Suggest why the Rf value for ethyl 3-oxobutanoate is significantly lower than 0.45 when just hexane is used as the solvent. (2)

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