Analytical techniques

9(a) PCl OR PCl OR SOCl [1] 1 5 3 2 9(b)(i) amide [1] 1 9(b)(ii) HCl / hydrogen chloride OR C H NH Cl / ethylammonium chloride [1] 1 2 5 3 9(c)(i) LiAl H [1] 1 4 9(c)(ii) reduction [1] 1 9(d)(i) relative abundance = 2 carbons × 1.1 × 0.62 1 = 1.36 / 1.4 [1] min 2sf 9(d)(ii) CH CH + / C H + [1] 2 3 2 2 5 © UCLES 2021 Page 13 of 16 9(e)(i) a [1] 1 9(e)(iii) d [1] 1 9(e)(iii) b, c, f [1] 1 9(e)(iv) f [1] 1 Question Answer Marks

8(a) M1 one diagram correct [1] 2 M2 both diagrams correct 3D and different [1] © UCLES 2021 Page 10 of 12 8(b) alanine because glutamic acid would have more than two / three peaks / absorbns / proton environments [1] 3 reason why alanine has a doublet given as one neighbouring proton [1] glutamic acid would have (two) triplet(s) OR a multiplet [1] reason why alanine has a quartet / quadruplet given as three neighbouring protons [1] 8(c)(i) 147 [1] 1 8(c)(ii) 88 = [H NCH(CH )CO H]+ [1] 2 2 2 2 131 = [CH(CH CH CO H)CO H]+ [1] 2 2 2 2 8(d)(i) use of buffer [1] 1 8(d)(ii) • correct circuit including DC power supply 2 • paper or gel labelled [1] • sample towards the middle of the paper / gel OR on cathode side [1] 8(d)(iii) anode / positive / + 1 AND anode / positive / + [1] 8(d)(iv) M1 ala is –1 and glu is –2 [1] 2 M2 ala is lighter / has lower M [1] r © UCLES 2021 Page 11 of 12

9(a) PCl OR PCl OR SOCl [1] 1 5 3 2 9(b)(i) amide [1] 1 9(b)(ii) HCl / hydrogen chloride OR C H NH Cl / ethylammonium chloride [1] 1 2 5 3 9(c)(i) LiAl H [1] 1 4 9(c)(ii) reduction [1] 1 9(d)(i) relative abundance = 2 carbons × 1.1 × 0.62 1 = 1.36 / 1.4 [1] min 2sf 9(d)(ii) CH CH + / C H + [1] 2 3 2 2 5 © UCLES 2021 Page 13 of 16 9(e)(i) a [1] 1 9(e)(iii) d [1] 1 9(e)(iii) b, c, f [1] 1 9(e)(iv) f [1] 1 Question Answer Marks

6(a) HOCH COOH + 2SOCl → ClCH COCl + 2SO + 2HCl 1 2 2 2 2 6(b) to remove / neutralise excess H+ / acid produced 1 OR to react with any acidic by-products / HCl / SO 2 OR to react with any unreacted W © UCLES 2022 Page 11 of 12 6(c) 4 M1: curly arrow from lone pair on :NH to carbonyl C(δ+)=O 2 M2: correct dipole on δ+C=Oδ– AND curly arrow from bond C=O to O(δ–) M3: correct structure of the intermediate (inc. charges) M4: curly arrow from lone pair on :O– to C=O AND curly arrow from C—Cl to Cl 6(d) N / nitrogen can donate its lone pair / LP / pair of electrons 1 6(e)(i) mobile = ethyl ethanoate 1 stationary = SiO / silica or Al O / alumina 2 2 3 6(e)(ii) R = distance travelled by solute / substance / compound / component 1 f ÷ distance travelled by solvent (front) 6(e)(iii) X is more attracted / more affinity / adsorbed more to the stationary phase 1 OR lidocaine dissolves better in the solvent ORA 6(f)(i) quartet AND triplet 1 6(f)(ii) • δ 7.1 = attached to aromatic ring / H—Ar 2 • δ 3.0 = alkyl next to C=O / —CH –C=O (2) • δ 2.3 = alkyl next to aromatic ring / H C–Ar (3) All three correct for two marks 6(f)(iii) 9 (nine) 1 © UCLES 2022 Page 12 of 12

7(a) TMS reference OR standard OR to define d = 0 1 D O solvent OR identification of O-H / N-H protons / group 2 © UCLES 2022 Page 12 of 16 7(b)(i) 2 number of peaks observed number of peaks observed in ketone in proton NMR spectrum carbon-13 NMR spectrum pentan-2-one 4 5 pentan-3-one 2 3 3-methylbutanone 3 4 three for one mark, six for two marks 7(b)(ii) M1 3-methylbutanone 2 M2 3-methylbutanone AND pentan-2-one 7(c)(i) six / 6 1 7(c)(ii) C H O 1 21 34 5 7(c)(iii) a substance that is able to rotate the plane of polarised light in opposite directions 1 Question Answer Marks

9(a)(i) stationary: non-volatile (non-polar) liquid 1 mobile: nitrogen / argon / any inert gas 9(a)(ii) the time that the substance stays in the column 1 OR time between injection and detection OWTTE © UCLES 2022 Page 15 of 16 9(a)(iii) areas are 30, 100, 25 OR 30, 150, 25 (½  b  h) OR 100 / 155 [1] 2 % of B = 100  (100 / 155) OR % of B = 100  150 / 205 = = 64.5 = 73.2 [1] ecf M1 areas 9(b) 5 5 5 4 4 2 9(c) 4 [1] 2 singlet, (two) triplet(s), multiplet (any order) [1] 9(d)(i) D = CH CH CO CH CH [1] E = (CH ) CHCO CH 2 3 2 2 2 3 3 2 2 3 9(d)(ii) O-CH labelled F 1 2 AND three protons on neighbouring carbon / adjacent CH 3 9(d)(iii) both CH in isopropyl group labelled G 1 3 AND alkane / alkyl (protons) © UCLES 2022 Page 16 of 16

8(a) C* marked on CH of T and nowhere else 1 8(b)(i) R – C H CH COCH CH [1] 2 6 5 2 2 3 3.7 is C H CH COCH CH 6 5 2 2 3 2.5 is C H CH COCH CH 6 5 2 2 3 1.0 is C H CH COCH CH [1] 6 5 2 2 3 8(b)(ii) singlet 1 and no H on neighbouring C 8(c)(i) P and T 1 8(c)(ii) P 1 8(d) CDCl or CCl 1 3 4 8(e) no difference and 1 no protons that exchange with D 8(f) 6 5 [1] 2 4 3 [1] © UCLES 2022 Page 10 of 11

9(a)(i) stationary: non-volatile (non-polar) liquid 1 mobile: nitrogen / argon / any inert gas 9(a)(ii) the time that the substance stays in the column 1 OR time between injection and detection OWTTE © UCLES 2022 Page 15 of 16 9(a)(iii) areas are 30, 100, 25 OR 30, 150, 25 (½  b  h) OR 100 / 155 [1] 2 % of B = 100  (100 / 155) OR % of B = 100  150 / 205 = = 64.5 = 73.2 [1] ecf M1 areas 9(b) 5 5 5 4 4 2 9(c) 4 [1] 2 singlet, (two) triplet(s), multiplet (any order) [1] 9(d)(i) D = CH CH CO CH CH [1] E = (CH ) CHCO CH 2 3 2 2 2 3 3 2 2 3 9(d)(ii) O-CH labelled F 1 2 AND three protons on neighbouring carbon / adjacent CH 3 9(d)(iii) both CH in isopropyl group labelled G 1 3 AND alkane / alkyl (protons) © UCLES 2022 Page 16 of 16

8(a)(i) 2 diagram has trailing bonds, two or more monomer residues AND either repeat unit correct OR ester linkage correct [1] diagram fully correct [1] © UCLES 2023 Page 11 of 14 8(a)(ii) condensation AND ester [1] 1 8(a)(iii) it is biodegradable because it can hydrolyse [1] 1 8(b)(i) d values: 3 12, 4.4 [1] 5.0, 1.6 [1] splitting patterns: singlet, quartet / quadruplet, singlet, doublet [1] 8(b)(ii) TMS / tetramethylsilane [1] 1 8(b)(iii) CDCl will not give an absorption / peak OR 1 3 CHCl will give an absorption / peak [1] 3 8(c)(i) time between injection and detection [1] 1 8(c)(ii) an unreactive gas AND a non-polar liquid [1] 1 8(c)(iii) area of peak divided by total area of all peaks  100% [1] 1 © UCLES 2023 Page 12 of 14

9(a) due to the electron-withdrawing effect/electronegative / –I effect of chlorine 1 AND stabilising the anion / carboxylate ion OR weakening the O-H bond 9(b)(i) (COOH) + 2SOCl → (COCl) + 2HCl + 2SO 1 2 2 2 2 9(b)(ii) 2 9(b)(iii) 2 M1 one correct repeat unit (within their structure) M2 the rest of the structure correct ecf on one incorrect monomer used [If structure partly or fully skeletal: continuation bonds must be dashed / wavy / different or have through brackets] 9(c)(i) CHI / triiodomethane 1 3 © Cambridge University Press & Assessment 2024 Page 14 of 15 9(c)(ii) 4 chemical shift splitting number of 1H atoms number of protons on () pattern responsible for the peak adjacent carbon atoms 1.15 triplet 3 2 2.25 singlet 3 0 3.60 singlet 2 0 3.95 quartet / quad 2 3 ruplet mark as any three [1] any six [2] any nine [3] all twelve [4] 9(c)(iii) 1 OR © Cambridge University Press & Assessment 2024 Page 15 of 15

6(a) C H Cl + AlCl → C H + + AlCl – [1] 1 2 5 3 2 5 4 OR C H Cl + FeCl → C H + + FeCl – 2 5 3 2 5 4 6(b)(i) 1 AND BOTH [1] 6(b)(ii) alkyl / ethyl group is 2,4 directing 1 OR ethyl group is electron donating / positive inductive effect [1] 6(c)(i) hot alkaline KMnO /MnO – (followed by acid) [1] 1 4 4 6(c)(ii) C H / C H (C H ) + 12 [O] → C H (COOH) + 2CO + 4H O 2 10 14 6 4 2 5 2 6 4 2 2 2 all species correct formulae C H + CO + H O [1] 10 14 2 2 correct balancing [1] 6(c)(iii) 4 [1] 1 6(d)(i) CDCl does not cause a peak 1 3 OR does not interfere with spectrum / peaks [1] 6(d)(ii) • ethylbenzene / C H C H 3 6 5 2 5 • triplet • CH 3 • 2H on neighbouring C / next to CH 2 – quartet / quadruplet – CH 2 – 3H on neighbouring C / next to CH / coupling by CH 3 3 any three [1] any five [2] all seven [3] © Cambridge University Press & Assessment 2024 Page 11 of 14 6(d)(iii) • benzene-1,2-dioic acid / C H (COOH) 1 6 4 2 • H on the benzene / C H 6 4 – COOH / carboxylic acid ALL three [1] 6(d)(iv) • COOH peak disappears OR remove peak at 13.1 (ecf (d)(iii) if  value used) 1 AND • as proton / hydrogen exchanges with deuterium / D BOTH [1] 6(e) dehydration / elimination / (auto)condensation [1] 1 Question Answer Marks

6(a) C H Cl + AlCl → C H + + AlCl – [1] 1 2 5 3 2 5 4 OR C H Cl + FeCl → C H + + FeCl – 2 5 3 2 5 4 6(b)(i) 1 AND BOTH [1] 6(b)(ii) alkyl / ethyl group is 2,4 directing 1 OR ethyl group is electron donating / positive inductive effect [1] 6(c)(i) hot alkaline KMnO /MnO – (followed by acid) [1] 1 4 4 6(c)(ii) C H / C H (C H ) + 12 [O] → C H (COOH) + 2CO + 4H O 2 10 14 6 4 2 5 2 6 4 2 2 2 all species correct formulae C H + CO + H O [1] 10 14 2 2 correct balancing [1] 6(c)(iii) 4 [1] 1 6(d)(i) CDCl does not cause a peak 1 3 OR does not interfere with spectrum / peaks [1] 6(d)(ii) • ethylbenzene / C H C H 3 6 5 2 5 • triplet • CH 3 • 2H on neighbouring C / next to CH 2 – quartet / quadruplet – CH 2 – 3H on neighbouring C / next to CH / coupling by CH 3 3 any three [1] any five [2] all seven [3] © Cambridge University Press & Assessment 2024 Page 11 of 14 6(d)(iii) • benzene-1,2-dioic acid / C H (COOH) 1 6 4 2 • H on the benzene / C H 6 4 – COOH / carboxylic acid ALL three [1] 6(d)(iv) • COOH peak disappears OR remove peak at 13.1 (ecf (d)(iii) if  value used) 1 AND • as proton / hydrogen exchanges with deuterium / D BOTH [1] 6(e) dehydration / elimination / (auto)condensation [1] 1 Question Answer Marks

6(a)(i) 2 M1: ester group in middle displayed between two monomers M2: rest of molecule correct (only one repeat unit) 6(a)(ii) cold acidified dilute KMnO / MnO – 1 4 4 6(b)(i) condensation OR dehydration OR elimination 1 6(b)(ii) species with two lone pairs / LP of electrons) 2 that form dative (covalent) / co-ordinate bond(s) to a (central) transition element / metal atom / ion 6(b)(iii) 2 M1 one correct diagram M2 correct diagram of the other optical isomer 6(c)(i) 8 / eight 1 6(c)(ii) to remove peaks / signals / absorptions 1 from acidic protons / OH / COOH / labile protons © Cambridge University Press & Assessment 2025 Page 13 of 14 6(c)(iii) Molecule must not be symmetrical (as eight different C environments) 4 Viable structures of X • methyl ketone / CH CO group 3 because (yellow) ppt / CHI formed (with alkaline I (aq)) 3 2 any two linked statements: • two —OH groups because 1H NMR signals lost in D O 2 • ketone / carbonyl / CH CO 3 as (13C NMR) signal with  = 205 / 190–220 ppm • methyl / carbon next to C=O because (13C NMR) signal with  = 30–65 ppm © Cambridge University Press & Assessment 2025 Page 14 of 14

7(a) 1,3-diethylbenzene 1 7(b)(i) CDCl 1 3 7(b)(ii) no difference AND no H that can be exchanged with D 1 7(b)(iii) 3  / ppm number of group name of protons responsible splitting pattern 1.3 6 CH triplet 3 2.7 4 CH quartet / quadruplet 2 7.1 4 Each correct column = [1] 7(b)(iv) 5 AND 6 1 7(c)(i) C H + 12[O] → C H O + 2CO + 4H O 1 10 14 8 6 4 2 2 © Cambridge University Press & Assessment 2025 Page 12 of 16 7(c)(ii) 3 compound G compound J compound K Each correct structure = [1] © Cambridge University Press & Assessment 2025 Page 13 of 16

8(a) reference: TMS / tetramethylsilane / (CH ) Si 1 3 4 AND solvent: D O / CDCl 2 3 © Cambridge University Press & Assessment 2025 Page 15 of 17 8(b) six / 6 peaks 1 8(c) 4 chemical splitting number of protons on number of 1H atoms shift pattern adjacent carbon responsible for the  / ppm atoms peak 1.10 triplet 2 3 1.50 doublet 1 6 2.45 quartet / quad 3 2 ruplet 3.75 multiplet 6 1 Any three [1] any six [2] any nine [3] all eleven [4] Question Answer Marks

7(a) 1,3-diethylbenzene 1 7(b)(i) CDCl 1 3 7(b)(ii) no difference AND no H that can be exchanged with D 1 7(b)(iii) 3  / ppm number of group name of protons responsible splitting pattern 1.3 6 CH triplet 3 2.7 4 CH quartet / quadruplet 2 7.1 4 Each correct column = [1] 7(b)(iv) 5 AND 6 1 7(c)(i) C H + 12[O] → C H O + 2CO + 4H O 1 10 14 8 6 4 2 2 © Cambridge University Press & Assessment 2025 Page 12 of 16 7(c)(ii) 3 compound G compound J compound K Each correct structure = [1] © Cambridge University Press & Assessment 2025 Page 13 of 16

6(a)(i) M1: (R f value) is distance moved by a component / spot / solute AND divided by distance moved by solvent 2 OR (R value) is the ratio of distance moved by a component / spot / solute AND by distance moved by solvent f M2: (retention time) is (the time) between injection and detection (of a component) © Cambridge University Press & Assessment 2025 Page 12 of 19 6(a)(ii) thin-layer chromatography: polar solvent OR non-polar solvent OR named solvent 1 gas-liquid chromatography: non-volatile liquid OR high boiling point liquid 6(b) A is more soluble in the mobile phase OR A has less adsorption to the stationary phase 1 6(c)(i) 1 6(c)(ii) M1: Y (two) singlet(s) 2 M2: Z triplet AND quartet © Cambridge University Press & Assessment 2025 Page 13 of 19

7(a) M1: Q CH CH CH(CH )CHO 2 3 2 3 M2: AND 7(b)(i) T CH CH CH COCH AND V (CH ) CHCOCH 1 3 2 2 3 3 2 3 7(b)(ii) • yellow solid 2 • CH CH CH COOH OR (CH ) CHCOOH 3 2 2 3 2 • CHI 3 Any two [1], all three [2] 7(c)(i) S (CH ) CCHO 1 3 3 © Cambridge University Press & Assessment 2025 Page 11 of 15 7(c)(ii) U CH CH COCH CH 1 3 2 2 3 7(c)(iii) triplet AND two hydrogen atoms on neighbouring carbon atoms 1 7(c)(iv) TMS / tetramethylsilane / Si(CH ) 1 3 4 7(d) 4 2 3 5 3 Any two [1], all four [2] Question Answer Marks

6(a)(i) M1: (R f value) is distance moved by a component / spot / solute AND divided by distance moved by solvent 2 OR (R value) is the ratio of distance moved by a component / spot / solute AND by distance moved by solvent f M2: (retention time) is (the time) between injection and detection (of a component) © Cambridge University Press & Assessment 2025 Page 12 of 19 6(a)(ii) thin-layer chromatography: polar solvent OR non-polar solvent OR named solvent 1 gas-liquid chromatography: non-volatile liquid OR high boiling point liquid 6(b) A is more soluble in the mobile phase OR A has less adsorption to the stationary phase 1 6(c)(i) 1 6(c)(ii) M1: Y (two) singlet(s) 2 M2: Z triplet AND quartet © Cambridge University Press & Assessment 2025 Page 13 of 19

8(a) tetramethylsilane 1 Only answer – correct spelling required. I TMS, (CH ) Si . 3 4 8(b)(i) 5 / five 1 8(b)(ii) 2 A douplet. proton environment name of splitting pattern I duplet, double, multiple, triple. w doublet A heptet / septet for multiplet. x multiplet y triplet z triplet ● ✓ ● ✓ 8(b)(iii)   5 –12 [1] 2 M1 requires this range instead a single value. M2 (N-H peak appears and) A M2 (N-H) proton / hydrogen exchanges with no proton / hydrogen exchanges / replaces / substitutes deuterium / D / D+ in D O. 2 with deuterium / D / D+ ora I proton / hydrogen is taken away / removed by the deuterium. 8(c) 2 I carboxylic acid (products isolated at pH 10). A carboxylate ion. A -ONa. CON –O–Na (covalent bond). M1M2 © Cambridge University Press & Assessment 2026 Page 23 of 25 Trace ID: PC-9D76E91B48 Re-uploading, mirroring or re-hosting this file on any other website or domain is unauthorised and traceable. Licensed for hosting on papacambridge.com only. P97a01p/4a2 CMaarkm Scbhermide gJuene 2·0 2p6 a| Spoaurccea: mpapbarciadmgbreid.gceo.comm 9701/42 Mark Scheme June 2026 Downloaded from PapaCambridge - https://papacambridge.com/

8(a) TMS / tetramethylsilane / (CH ) Si 1 3 4 8(b)(i) M1 Q and (peak at) 5.4 / 4.5–7.0 = Ar-OH / phenol 2 I Q and 4 peaks for 4 (proton) environments M2 Q and (peak(s)) at 6.8–7.3 / 6.0–9.0 = aromatic / H–Ar (question asks for protons responsible). If explanation is blank, check spectra. A benzene ring for aromatic. 8(b)(ii) • triplet 2 • two protons/H on neighbouring/adjacent C A neighbouring CH 2 or CH 3 for adjacent. • quartet A quadruplet for quartet. • three protons/H on neighbouring/adjacent C A near-miss spellings (e.g. one letter missing / incorrect only or ‘tirplet’, etc.). ✓ ✓ ⚫ ⚫ 8(c) peak (at 5.4) disappears 1 A chemical shift disappears. and I it would have 3 or 4 peaks as we don’t the OH / 5.4 proton / H is liaible or know if they are counting the TMS peak. the OH / 5.4 proton / H exchanges / replaced with D or I OH exchanges with D O. 2 equation, e.g. ROH + D O → ROD + DHO I (OH) reacts with D O. 2 2 I OH exchanges with OD. CON incorrect peak / spectra. © Cambridge University Press & Assessment 2026 Page 18 of 21 Trace ID: PC-0F078E40FE Re-uploading, mirroring or re-hosting this file on any other website or domain is unauthorised and traceable. Licensed for hosting on papacambridge.com only. P97a01p/4a4 CMaarkm Scbhermide gJuene 2·0 2p6 a| Spoaurccea: mpapbarciadmgbreid.gceo.comm 9701/44 Mark Scheme June 2026 Downloaded from PapaCambridge - https://papacambridge.com/ 8(d) ethanoic acid phenol ethanol 4 • correct reference to O-H bond strength / anion stability A ecf for matching O–H strength / anion stability correctly to incorrect order for bullet 1. • (ethanoic acid) C=O has electron withdrawing / –I effect CON bullet 1 for incorrect reference to O–H bond strength / anion stability. I COOH / COO– is an electron withdrawing group. A e– / negative charge delocalises over COO– / C=O. • (phenol) LP/p-orbital on O overlaps/is delocalised and with/into ring/ system • (ethanol) electron donating/+I effect of alkyl/R/CH /CH /C H 2 3 2 5 ✓ ✓ ✓ for four bullets ⚫