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Topical›Chemistry 9701›An introduction to AS Level organic chemistry›Isomerism: structural isomerism and stereoisomerism›Paper 1

Isomerism: structural isomerism and stereoisomerism — Paper 1 · A Level Chemistry 9701

13.4· 230 questions · 230 marks · 276 min · 2005–2025· Multiple choice

Every Cambridge A Level Chemistry Paper 1 question on isomerism: structural isomerism and stereoisomerism, laid out as 55 A4 pages with the mark scheme below. Nothing is left out. Free to read, no account.

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Question 1: The diagram shows the structure of vitamin C. HO OH C C O C CH CH CH2OH O OH How many chiral centres are there in one molecule?Question 2: What is the number of isomers of C2H2Cl2 including cis-trans isomers? A 2 B 3 C 4 D 5Question 3: The sex-attractant of the house-fly is muscalure, with the following formula. CH3(CH2)7CH = CH(CH2)12CH3 Which statements about muscalure a…Question 4: Warfarin is used as a rat poison. O O C C C CH CH2 C CH3 OH O warfarin How many chiral centres are present in the warfarin molecule? A 0 B …Question 5: The structures below show isomers of C6H12. 1 2 3 4 CH3 CH3 CH3 C2H5 C2H5 H C2H5 CH3 C C C C C C C C H C2H5 H CH3 CH3 CH3 H CH3 In which pa…1 / 55
Question 6: In which pairs are the members stereoisomers of each other? 1 CH3 CH3 C C Br Br H Cl Cl H 2 CH3 Br Br CH3 C C C C H H H H 3 CH3 Br CH3 H C …Question 7: What is the total number of different chloroethanes, formula C2H6-nCln, where n can be any integer from 1 to 4? A 4 B 6 C 7 D 8Question 8: Which alkene could exist in cis and trans forms? A CH3CH2CH2CH CH2 B CH3CH2CH CHCH3 C CH3CH2C CH2 CH3 D CH3CH CCH3 CH3Question 9: Which molecules, each with a linear carbon chain, can have an optically active isomer? I II III IV C3H6BrI C3H4BrI C3H6I2 C3H4Br2 A I and I…2 / 55
Question 10: In which pair do the isomers have identical boiling points? A CH3CH2CH2CH2OH and (CH3)2CHCH2OH B CH3(CH2)4CH3 and (CH3)…Question 11: Trichloroethene is widely used as a dry-cleaning agent. H Cl \ 4 C=C Ve C Cl With which of the following does trichloroethene react to give…Question 12: Sorbitol is a naturally-occurring compound with a sweet taste. It is often used as a substitute for sucrose by the food industry. The diagr…Question 13: Which hydrocarbon can form a monochloro-substitution derivative which shows both chirality and cis-trans isomerism? A CH3CH=CH2 B (CH3)2C=C…3 / 55
Question 14: In recent years a number of athletes have been banned from sports because of their illegal use of synthetic testosterone, a naturally occur…Question 15: The compound known as ‘gamma-linolenic acid’ is found in significant amounts in the seeds of the Evening Primrose plant. There is evidence …Question 16: The drug cortisone has the formula shown. CH2OH CO CH3 OH O CH3 O In addition to those chiral centres marked by an asterisk (*), how many o…4 / 55
Question 17: The presence of 11-cis retinal, C20H28O, in cells in the eye is important for vision. The structure of retinal includes an aldehyde group, …Question 18: What is the least number of carbon atoms in a non-cyclic alkane molecule that has a chiral centre? A 7 B 8 C 9 D 10Question 19: When heated with chlorine, the hydrocarbon 2,2-dimethylbutane undergoes free radical substitution. In a propagation step the free radical X…Question 20: Which isomer of C4H10O forms three alkenes on dehydration? A butan-1-ol B butan-2-ol C 2-methylpropan-1-ol D 2-methylpropan-2-ol5 / 55
Question 21: Which compound exhibits both cis-trans and optical isomerism? A CH3CH=CHCH2CH3 B CH3CHBrCH=CH2 C CH3CBr=CBrCH3 D CH3CH2CHBrCH=CHBrQuestion 22: Which isomer of C4H10O forms three alkenes on dehydration? A butan-1-ol B butan-2-ol C 2-methylpropan-1-ol D 2-methylpropan-2-olQuestion 23: Which compound exhibits both cis-trans and optical isomerism? A CH3CH=CHCH2CH3 B CH3CHBrCH=CH2 C CH3CBr=CBrCH3 D CH3CH2CHBrCH=CHBrQuestion 24: When heated with chlorine, the hydrocarbon 2,2-dimethylbutane undergoes free radical substitution. In a propagation step the free radical X…Question 25: Which compound exhibits both cis-trans and optical isomerism? A CH3CH=CHCH2CH3 B CH3CHBrCH=CH2 C CH3CBr=CBrCH3 D CH3CH2CHBrCH=CHBr6 / 55
Question 26: Lactic acid occurs naturally, for example in sour milk. H H O O H C C C H H O H lactic acid What is a property of lactic acid? A It decolou…Question 27: The compound 2-methylpropene, C4H8, is a monomer used in the production of synthetic rubber. H CH3 C C H CH3 In addition to 2-methylpropene…Question 28: How many structural isomers are there of trichloropropane, C3H5Cl 3? A 3 B 4 C 5 D 6Question 29: CH3CH2COCH2CH3 reacts with hydrogen cyanide to form a cyanohydrin. Which feature applies to the product? A It has one chiral centre. B It i…7 / 55
Question 30: Which of the compounds shown have chiral carbon atoms? 1 2 3 4 OH O CH3 CH3 CH3 CH3 OH A 1, 2, 3 and 4 B 1 and 4 only C 2 and 3 only D 2, 3…Question 31: The compound 2-methylpropene, C4H8, is a monomer used in the production of synthetic rubber. H CH3 C C H CH3 In addition to 2-methylpropene…Question 32: Pentanol, C5H11OH, has four structural isomers that are primary alcohols. How many of these primary alcohols contain a chiral carbon atom? …8 / 55
Question 33: The diagram shows the structure of the naturally-occurring molecule cholesterol. H3C CH3 H CH3 H H H HO cholesterol Student X claimed that …Question 34: Which isomer of C6H13OH gives the greatest number of different alkenes when it is dehydrated? A B CH3 CH3 CH CH CH2OH CH3 CH2 CH2 CH CH2 CH…Question 35: Which alkenes, on reaction with steam at 600 K and 6 x 106 Pa pressure in the presence of a phosphoric acid catalyst, could produce an alco…Question 36: Which compound does not show cis-trans isomerism? A 2-methylpent-2-ene B 3-methylpent-2-ene C 3,4-dimethylhex-3-ene D pent-2-ene9 / 55
Question 37: How many isomers with the formula C5H10 have structures that involve π bonding? A 3 B 4 C 5 D 6Question 38: Pentanol, C5H11OH, has four structural isomers that are primary alcohols. How many of these primary alcohols contain a chiral carbon atom? …Question 39: The diagram shows the structure of the naturally-occurring molecule cholesterol. H3C CH3 H CH3 H H H HO cholesterol Student X claimed that …Question 40: Which alkenes, on reaction with steam at 600 K and 6 x 106 Pa pressure in the presence of a phosphoric acid catalyst, could produce an alco…Question 41: A reaction between chlorine and propane in ultraviolet light produces two isomeric monochloropropanes, C3H7Cl, as products. Which informati…10 / 55
Question 42: Disaccharides, C12H22O11, are important in the human diet. For example, sucrose is found in pastries and lactose occurs in milk products. B…Question 43: The use of sucrose in food processing depends in part on osmotic pressure, symbol Π. In dilute solution, Π varies with concentration in a s…Question 44: The molecule shown is optically active. Cl H Cl H H Cl C C C C C Cl H H H H Cl C H H How many chiral carbon atoms are present in this molec…11 / 55
Question 45: A reaction between chlorine and propane in ultraviolet light produces two isomeric monochloropropanes, C3H7Cl, as products. Which informati…Question 46: Disaccharides, C12H22O11, are important in the human diet. For example, sucrose is found in pastries and lactose occurs in milk products. B…Question 47: How many isomeric esters have the molecular formula C4H8O2? A 2 B 3 C 4 D 5Question 48: What are the same for a pair of optical isomers? 1 their empirical formula 2 their functional groups 3 their structural formula12 / 55
Question 49: Compound C is used in textile and leather processing. O O C CH2 compound C H2C C O O Which starting material(s), on gentle heating with a f…Question 50: How many isomeric esters have the molecular formula C4H8O2? A 2 B 3 C 4 D 5Question 51: Which compound, on reaction with hydrogen cyanide, produces a compound with a chiral centre? A CH3CHO B CH3CH2COCH2CH3 C CH3CO2CH3 D HCHOQuestion 52: An alkene has the formula CH3CH=CR CH2CH3 and does not possess cis-trans isomers. What is R ? A H B Cl C CH3 D C2H5Question 53: The cracking of a single hydrocarbon molecule, CnH2n+2, produces two hydrocarbon molecules only. Each hydrocarbon product contains the same…Question 54: An alkene has the formula CH3CH=CR CH2CH3 and does not possess cis-trans isomers. What is R ? A H B Cl C CH3 D C2H5Question 55: The cracking of a single hydrocarbon molecule, CnH2n+2, produces two hydrocarbon molecules only. Each hydrocarbon product contains the same…13 / 55
Question 56: The following compounds are found in the seaweed Asparagopsis taxiformis. Which compound could show both cis-trans isomerism and optical is…Question 57: Some vegetable oils contain ‘trans fats’ that are associated with undesirable increases in the amount of cholesterol in the blood. In the d…Question 58: How many isomers, including structural and stereoisomers, with the formula C4H8 have structures that involve π bonding? A 1 B 2 C 3 D 4Question 59: How many isomeric esters, including structural isomers and stereoisomers, can be made with the molecular formula C5H10O2, if methanoic acid…Question 60: Which compound exhibits stereoisomerism? A CH3CHCl CH3 B CH3CHCl CH2Cl C CH3CCl 2CH3 D CH2Cl CH2CH2Cl14 / 55
Question 61: What are the only structures formed when butan-2-ol is heated with concentrated H2SO4? CH3CH2 H CH3 H A C C C C H H H CH3 CH3 CH3 CH3 H H H…Question 62: The compounds below are treated with hydrogen cyanide. Which compounds react and produce a molecule containing a chiral centre? 1 butanal 2…Question 63: Which compound exhibits stereoisomerism? A CH3CHCl CH3 B CH3CHCl CH2Cl C CH3CCl 2CH3 D CH2Cl CH2CH2Cl15 / 55
Question 64: What are the only structures formed when butan-2-ol is heated with concentrated H2SO4? CH3CH2 H CH3 H A C C C C H H H CH3 CH3 CH3 CH3 H H H…Question 65: Including structural and stereoisomers, how many isomers are there of C2H2Br2? A 2 B 3 C 4 D 5Question 66: Including structural and stereoisomers, how many isomeric products are produced when alcoholic KOH reacts with 2-chlorobutane? A 1 B 2 C 3 …Question 67: An alcohol with molecular formula CnH2n+1OH has a chiral carbon atom but does not react with hot, acidified K2Cr2O7. What is the smallest p…Question 68: The reaction of ethanal, CH3CHO, with HCN to form a cyanohydrin is catalysed by NaCN. What are features of the intermediate of this reactio…16 / 55
Question 69: The structural formulae of two compounds are shown below. O O CH3CH2CH2CH2CH2C CH3CH2CH2CH2CH2OC OH H Which statements about these compound…Question 70: There are three structural isomers with the formula C5H12. Which formulae correctly represent these three structural isomers? A CH3CH2CH2CH…Question 71: CH3CH2COCH2CH3 reacts with hydrogen cyanide to form an organic product called a cyanohydrin. Which feature applies to the cyanohydrin produ…Question 72: How many geometrical (cis-trans) isomers are there of hex-2,4-diene, CH3CH=CHCH=CHCH3? A none; hex-2,4-diene does not show geometric isomer…Question 73: Which alcohol has a chiral centre and can be oxidised to a ketone? A pentan-2-ol B pentan-3-ol C 3-methylhexan-1-ol D 3-methylhexan-3-ol17 / 55
Question 74: Methylpropan-1-ol and butan-1-ol are structural isomers. Methylpropan-1-ol has a lower boiling point. Which statement explains why the boil…Question 75: Considering only structural isomers, what is the number of alcohols of each type with the formula C5H12O? primary secondary tertiary A 3 3 …Question 76: Methylpropan-1-ol and butan-1-ol are structural isomers. Methylpropan-1-ol has a lower boiling point. Which statement explains why the boil…Question 77: Considering only structural isomers, what is the number of alcohols of each type with the formula C5H12O? primary secondary tertiary A 3 3 …Question 78: In this question, structural isomerism and stereoisomerism should be considered. How many isomeric aldehydes have the formula C5H10O? A 3 B…18 / 55
Question 79: The compound known as ‘gamma-linolenic acid’ is found in the seeds of the evening primrose plant. CH3(CH2)4CH=CHCH2CH=CHCH2CH=CH(CH2)4CO2H …Question 80: The diagram shows the structure of the naturally-occurring molecule cholesterol. H3C CH3 H CH3 H H H HO cholesterol Student X stated that t…Question 81: Methyl butanoate, C5H10O2, is an ester used in the food industry to give products the flavour of apples. O H H H H C C C C H H C O H H H H …19 / 55
Question 82: Propanal will react with hydrogen cyanide to form 2-hydroxybutanenitrile. A suitable catalyst for this reaction is sodium cyanide. NaCN CH3…Question 83: In 1869 Ladenburg suggested a structure for benzene, C6H6, in which one hydrogen atom is attached to each carbon atom. CH HC CH CH HC CH La…Question 84: The diagram shows the structure of an alkene molecule. CH3 CH3 CH3 C C H C C H H H CH3 Which statements about this molecule are correct? 1 …Question 85: Which statements about 2-methylbutan-1-ol are correct? 1 It can give HCl (g) on reaction with PCl 5. 2 It can be oxidised to give an aldehy…20 / 55
Question 86: Which compound shows optical isomerism? A 2-chloropropane B 1,2-dichloropropane C 1,3-dichloropropane D 2,2-dichloropropaneQuestion 87: Compound Q is obtained by adding H2O across the double bond in compound P. OH P Q Which statements about these two compounds are correct? 1…Question 88: Geraniol and nerol are compounds found in some flower fragrances. They are isomers of each other. CH3 CH3 C CH2OH C H H2C C H2C C H CH2OH H…21 / 55
Question 89: The diagrams show two different compounds. O O 1 2 What is ● the total number of structural isomers, including compound 2, that could be fo…Question 90: Geranyl ethanoate is present in ginger and cocoa, and is used in shampoos and soaps as a perfume. It reacts with an excess of bromine in an…Question 91: How many isomeric esters, including structural isomers and stereoisomers, can be made with the molecular formula C5H10O2, if methanoic acid…22 / 55
Question 92: The diagram shows the structure of 1,3-butadiene. H H C C H H C C H H 1,3-butadiene The addition reaction between 1,3-butadiene and two mol…Question 93: The structural formulae of two compounds are shown below. O O CH3CH2CH2CH2CH2C CH3CH2CH2CH2CH2OC OH H Which statements about these compound…Question 94: In 1865 Kekulé suggested a ring structure for benzene, C6H6, in which a hydrogen atom is attached to each carbon atom. H H C H C C C C H C …23 / 55
Question 95: In 1865 Kekulé suggested a ring structure for benzene, C6H6, in which a hydrogen atom is attached to each carbon atom. H H C H C C C C H C …Question 96: Geraniol and linalool are compounds found in some flower fragrances. CH3 CH3 HO C CH2OH C H2C C H2C C H H2C H H2C CH2 CH CH C C H3C CH3 H3C…Question 97: Structural isomerism and stereoisomerism should be considered when answering this question. Which formula identifies a single substance? A …24 / 55
Question 98: Structural isomerism and stereoisomerism should be considered when answering this question. If a molecule contains two non-identical chiral…Question 99: How many esters with the molecular formula C5H10O2 can be made by reacting a primary alcohol with a carboxylic acid? A 4 B 5 C 6 D 8Question 100: Which compounds, on heating with ethanolic NaOH, produce more than one product with molecular formula C4H8? 1 2-bromobutane 2 2-bromo-2-met…Question 101: The structural formula of compound Q is shown. O Q How many stereoisomers exist with this structural formula? A 1 B 2 C 4 D 8Question 102: What is the name of compound X? OH compound X A trans-2-hydroxyhex-3-ene B trans-2-hydroxyhexene C trans-5-hydroxyhex-3-ene D trans-5-hydro…25 / 55
Question 103: In which molecules do all the carbon atoms lie in the same plane? 1 2,3-dimethylbut-2-ene 2 propane 3 cyclohexaneQuestion 104: The reaction of ethanal, CH3CHO, with HCN to form 2-hydroxypropanenitrile is catalysed by NaCN. What are features of the intermediate of th…Question 105: Which compound does not exhibit stereoisomerism? A CH3CHCl CH2CHO B CH3CHCHCH3 C CH2Cl CH2CCl 2H D CHCl CHClQuestion 106: The structural formula of compound Q is shown. O Q How many stereoisomers exist with this structural formula? A 1 B 2 C 4 D 8Question 107: What is the name of compound X? OH compound X A trans-2-hydroxyhex-3-ene B trans-2-hydroxyhexene C trans-5-hydroxyhex-3-ene D trans-5-hydro…26 / 55
Question 108: In which molecules do all the carbon atoms lie in the same plane? 1 2,3-dimethylbut-2-ene 2 propane 3 cyclohexaneQuestion 109: The reaction of ethanal, CH3CHO, with HCN to form 2-hydroxypropanenitrile is catalysed by NaCN. What are features of the intermediate of th…Question 110: Which types of stereoisomerism are shown by 2,4-dimethylhex-2-ene? A both cis-trans isomerism and optical isomerism B cis-trans isomerism o…Question 111: Structural isomerism and stereoisomerism should be considered when answering this question. The molecular formula of compound X is C5H12O. …27 / 55
Question 112: Fructose is a sugar with more than one chiral centre. The fructose molecule is shown with X, Y and Z indicating three carbon atoms. OH H C …Question 113: Which pair of alcohols are isomers of each other? A butan-1-ol and 2,2-dimethylpropan-1-ol B butan-2-ol and 2-methylpropan-2-ol C pentan-1-…Question 114: Which alcohol can be dehydrated to give two products which are structural isomers of each other? A B C D H H H H H H CH3 H H H H CH3 H C C …Question 115: Compound Y is treated with an excess of hydrogen gas in the presence of a nickel catalyst. The product is fully saturated. compound Y What …28 / 55
Question 116: Structural isomerism and stereoisomerism should be considered when answering this question. A colourless liquid, C5H11Cl , exists as a mixt…Question 117: Which statement about butanone is correct? A Butanone can be dehydrated by concentrated sulfuric acid to give CH2=CHCH=CH2. B Butanone give…Question 118: Which compounds show geometrical (cis-trans) isomerism? 1 CH3CH=C(CH3)C2H5 2 CH3CH=CHCH2CH2CH3 3 C2H5CH=CHC2H5Question 119: Molecule G is shown. O O G How many chiral centres are present in each molecule of G? A 1 B 2 C 3 D 4Question 120: Considering only structural isomers, what is the number of alcohols of each type with the formula C5H12O? primary secondary tertiary A 3 3 …29 / 55
Question 121: Which compounds, on reaction with NaBH4, form a compound with a chiral carbon atom? 1 CH3CH2CH2COCH3 2 CH2CHCOCH2CH3 3 CH3CH2COCH2CH3Question 122: Compound Y is a straight chain molecule with formula CnH2n+1X. X is a halogen. The Mr of Y is 137. The halogen atom is on the second carbon…Question 123: X has the molecular formula C5H12O. X has a branched carbon skeleton and a secondary alcohol functional group. How many structural isomers …Question 124: A new jet fuel has been produced that is a mixture of different structural isomers of compound Q. Q Which skeletal formula represents a str…30 / 55
Question 125: There are three structural isomers with the formula C5H12. Which formulae correctly represent these three structural isomers? A CH3CH2CH2CH…Question 126: X has the molecular formula C5H12O. X has a branched carbon skeleton and a secondary alcohol functional group. How many structural isomers …Question 127: A new jet fuel has been produced that is a mixture of different structural isomers of compound Q. Q Which skeletal formula represents a str…Question 128: Which compound shows optical isomerism and gives a positive test with alkaline aqueous iodine? A CH3COCH(OH)CH3 B CH3COCH2CH2OH C HOCH2CH(C…31 / 55
Question 129: How many structural isomers are there of trichloropropane, C3H5Cl 3? A 3 B 4 C 5 D 6Question 130: Structural isomerism and stereoisomerism should be considered when answering this question. 2-bromopentane is heated with an excess of etha…Question 131: The diagrams show two different compounds. O O 1 2 What is ● the total number of structural isomers, including compound 2, that could be fo…Question 132: Which compound has the molecular formula C6H10O? A B C D O O O OHQuestion 133: Structural isomerism and stereoisomerism should be considered when answering this question. 3-methylhexan-3-ol reacts with hot, concentrate…32 / 55
Question 134: Compound X does not show cis-trans isomerism. What could be the identity of compound X? A 1,1,2-trichloropropene B 1,2,3-trichloropropene C…Question 135: The diagram shows the repeat unit of an addition polymer. C2H5 CH3 C C CH3 C2H5 n What is the correct name for the monomer that would form …Question 136: Structural isomerism and stereoisomerism should be considered when answering this question. Which isomer of C6H13OH gives the greatest numb…Question 137: Structural isomerism only should be considered when answering this question. A set of isomeric compounds, with molecular formula C5H10O, al…Question 138: Which substance reacts with trichloroethene to give a chiral product? A Br2 B HCl C NaCN D NaOH33 / 55
Question 139: The structure of tiglic acid is CH3CH=C(CH3)CO2H. Which statements about the properties of one molecule of this acid are correct? 1 It cont…Question 140: Structural isomerism and stereoisomerism should be considered when answering this question. How many isomers with the formula C5H10 have st…Question 141: Compound X has stereoisomers and forms a precipitate when warmed with Fehling’s reagent. What could be the structure of compound X? A B C D…Question 142: Which substance reacts with trichloroethene to give a chiral product? A Br2 B HCl C NaCN D NaOHQuestion 143: Which compounds, on heating with an excess of concentrated sulfuric acid, produce only one product with molecular formula C7H10? 1 2 3 OH O…Question 144: Which pair of compounds are functional group isomers of each other? A butan-1-ol and butanal B ethylpropanoate and pentanoic acid C hex-1-e…Question 145: Structural isomerism and stereoisomerism should be considered when answering this question. How many non-cyclic isomers have the molecular …34 / 55
Question 146: Which statement is correct? A 2,2-dimethylpropanoic acid is an isomer of propyl methanoate. B 2-methylbutan-2-ol is an isomer of hexan-3-ol…Question 147: But-1-ene and but-2-ene are treated separately with cold, dilute acidified manganate(VII) ions. Four students, W, X, Y and Z, make statemen…Question 148: A mixture of the three isomers of C2H2Cl 2 is polymerised. Which sequences will be seen within the polymer chains? 1 2 3 Cl H H H Cl H C C …Question 149: The structure of damascenone is shown. damascenone O Including damascenone, how many stereoisomers exist with this structural formula? A 1 …Question 150: How many isomeric esters have the molecular formula C4H8O2? A 2 B 3 C 4 D 5Question 151: Structural and stereoisomerism should be considered when answering this question. When trans-pent-2-ene reacts with HBr, how many different…35 / 55
Question 152: Which statement about compound T and compound U is correct? compound T compound U O O H3C C H C CH2CH2CH3 CH(CH3)CH2CH3 A T and U are stere…Question 153: Which pairs are structural isomers of each other? 1 CH3CH2CH2CH2CH2CO2H and CH3CH2CH2CO2CH2CH3 2 and 3 CH3CH2CH2CH(OH)CH2CH3 and CH3CH2…Question 154: Structural and stereoisomerism should be considered when answering this question. Compounds X, Y and Z are shown. X Y Z HO HO Cl H H Cl Cl …Question 155: Two students each make a statement about 2-methylbut-1-ene. Student 1 states that 2-methylbut-1-ene has geometrical isomers. Student 2 stat…36 / 55
Question 156: During the bromination of methane, the free radical CH3• is generated. A possible termination step of this reaction is the formation of C2H…Question 157: The unsaturated hydrocarbon octa-1,3,5,7-tetraene, C8H10, can display geometric isomerism. octa-1,3,5,7-tetraene CH2=CHCH=CHCH=CHCH=CH2 How…Question 158: How many structural isomers are there of molecular formula C5H10O that give a red precipitate with Fehling’s solution? A 1 B 2 C 3 D 4Question 159: Which substances have molecular formula C4H8O? 1 O 2 O OH 3Question 160: Structural and stereoisomerism should be considered when answering this question. Compounds X, Y and Z are shown. X Y Z HO HO Cl H H Cl Cl …37 / 55
Question 161: Two students each make a statement about 2-methylbut-1-ene. Student 1 states that 2-methylbut-1-ene has geometrical isomers. Student 2 stat…Question 162: During the bromination of methane, the free radical CH3• is generated. A possible termination step of this reaction is the formation of C2H…Question 163: The structures of citric acid and isocitric acid are shown. citric acid isocitric acid CH2CO2H CH2CO2H C(OH)CO2H CHCO2H CH2CO2H CH(OH)CO2H …Question 164: How many tertiary alcohols have the molecular formula C6H14O? A 1 B 2 C 3 D 4Question 165: Which compound could show both cis-trans isomerism and optical isomerism? A B C D Cl Cl O Br Cl H H H Br Br Br C Br C C C Br C C C Br C C B…38 / 55
Question 166: Alcohol X reacts with concentrated sulfuric acid to produce a mixture of products. Two of the products are structural isomers of each other…Question 167: Which compound shows stereoisomerism? A 2-methylbut-2-ene B 2-chloropropan-1-ol C difluorochlorobromomethane D pent-1-eneQuestion 168: Structural isomerism only should be considered when answering this question. Molecule X contains three C=C double bonds. One mole of X is r…Question 169: Structural isomerism and stereoisomerism should be considered when answering this question. A colourless liquid, C5H11Cl , exists as a mixt…39 / 55
Question 170: CH3CH2COCH2CH3 reacts with hydrogen cyanide to form an organic product called a cyanohydrin. Which statement is correct? A The cyanohydrin …Question 171: A diketo acid is a compound with two ketone groups and one carboxylic acid group. limonene terpinolene Which statements about the reactions…Question 172: The formula of hydrocortisone acetate is shown. hydrocortisone acetate O CH2OCOCH3 CH3 HO OH CH3 O Which row is correct? number of C atoms …40 / 55
Question 173: Structural and stereoisomerism should be taken into account when answering this question. Y is a gaseous hydrocarbon which decolourises aqu…Question 174: What is the same for a pair of optical isomers? 1 their empirical formula 2 their functional groups 3 their structural formulaQuestion 175: Structural isomerism only should be considered when answering this question. Molecule X contains three C=C double bonds. One mole of X is r…Question 176: Structural isomerism and stereoisomerism should be considered when answering this question. A colourless liquid, C5H11Cl , exists as a mixt…Question 177: CH3CH2COCH2CH3 reacts with hydrogen cyanide to form an organic product called a cyanohydrin. Which statement is correct? A The cyanohydrin …41 / 55
Question 178: A diketo acid is a compound with two ketone groups and one carboxylic acid group. limonene terpinolene Which statements about the reactions…Question 179: How many esters have the molecular formula C4H8O2? A 2 B 3 C 4 D 5Question 180: Structural isomerism and stereoisomerism should be taken into account when answering this question. How many isomeric alkenes with formula …Question 181: A skeletal formula is shown. What is the total number of stereoisomers including the one shown? A 4 B 6 C 8 D 16Question 182: Compound Z, C7H13Br, has two chiral centres. A sample of Z contains all four possible optical isomers. This sample of Z reacts with hot eth…42 / 55
Question 183: Structural isomerism and stereoisomerism should be considered when answering this question. Y is a gaseous hydrocarbon which decolourises a…Question 184: Structural isomerism only should be considered when answering this question. Several compounds with molecular formula C4H8O2 have one carbo…Question 185: Which pair of alcohols are isomers of each other? A butan-1-ol and 2,2-dimethylpropan-1-ol B butan-2-ol and 2-methylpropan-2-ol C pentan-1-…Question 186: Structural isomerism and stereoisomerism should be considered when answering this question. How many isomeric compounds with molecular form…Question 187: The monomer buta-1,3-diene can undergo addition polymerisation in various ways. Two of the polymers that can be made are called cis-poly(bu…43 / 55
Question 188: The structure of tartaric acid is shown. tartaric acid OH O HO OH O OH Which statements about tartaric acid are correct? 1 A molecule of ta…Question 189: Which pair includes a hydrocarbon without a chiral centre? A CH3CH2CH2CH(CH3)CH2CH3 CH3CH(CH3)CH(CH3)CH2CH3 B CH3CH2CH2CH(CH2CH3)CH3 CH3CH2…Question 190: Structural isomerism and stereoisomerism should be considered when answering this question. 3-methylhexan-3-ol reacts with hot concentrated…Question 191: Which pair of alcohols are isomers of each other? A butan-1-ol and 2,2-dimethylpropan-1-ol B butan-2-ol and 2-methylpropan-2-ol C pentan-1-…Question 192: Structural isomerism and stereoisomerism should be considered when answering this question. How many isomeric compounds with molecular form…44 / 55
Question 193: The monomer buta-1,3-diene can undergo addition polymerisation in various ways. Two of the polymers that can be made are called cis-poly(bu…Question 194: Which two formulae correctly represent a pair of structural isomers? A CH3CH(CH3)COOH and (CH3)2CHCOOH B CH3CH(COOH)CH3 and (CH3)2CHCOOH C …Question 195: Compound X, C7H13Br, reacts with hot alcoholic NaOH to produce two compounds, Y and Z. On reaction with Br2, Y gives a product, C7H12Br2, w…Question 196: Cyclohexene, C6H10, is a hydrocarbon with a six-membered ring of carbon atoms. It has several structural isomers that are straight-chain al…45 / 55
Question 197: Structural and stereoisomerism should be considered when answering this question. P has molecular formula C5H10O. P produces an orange prec…Question 198: Structural isomerism and stereoisomerism should be considered when answering this question. 2-bromopentane is heated with an excess of etha…Question 199: When 1-methylcyclohexene reacts with Br, the product is X. When 1-methylcyclohexene reacts with HBr the major product is Y. Br, HBr xX ——…Question 200: An unsaturated carboxylic acid reacts with alcohol X to form an ester. The structure of the ester is shown. 2 2 Which geometrical isomer is…46 / 55
Question 201: The compound aspartame is widely used as a sweetener in ‘diet’ soft drinks. aspartame CH3 O O O HO C6H5 NH O NH2 Aspartame is chiral. (Ther…Question 202: Artemisinin is a powerful anti-malarial drug. artemisinin CH3 O O CH3 O O O CH3 How many chiral centres are there in each molecule of artem…Question 203: How many geometrical (cis/trans) isomers are there of hex-2,4-diene, CH3CH=CHCH=CHCH3? A none; hex-2,4-diene does not show geometric isomer…Question 204: How many esters with the molecular formula C5H10O2 can be made by reacting a primary alcohol with a carboxylic acid? A 4 B 5 C 6 D 847 / 55
Question 205: The compound aspartame is widely used as a sweetener in ‘diet’ soft drinks. aspartame CH3 O O O HO C6H5 NH O NH2 Aspartame is chiral. (Ther…Question 206: The diagram shows the structure of the naturally occurring molecule cholesterol. cholesterol H3C CH3 CH3 HO Student X stated that the 17 ca…Question 207: Structural isomerism only should be considered when answering this question. How many compounds with molecular formula C5H11Br are primary …48 / 55
Question 208: Structural isomerism and stereoisomerism should be taken into account when answering this question. The structure of 3-methylcyclobutene is…Question 209: Compound T has the skeletal formula shown. compound T Which structure is a structural isomer of compound T? A B C DQuestion 210: A sample of pent-2-en-4-ol, C5H10O, contains all the possible stereoisomers of this compound. How many stereoisomers are there in the sampl…Question 211: Which alkene shows geometric isomerism? A CH3CH2CH2CH CH2 B CH3CH2CH CHCH3 C CH3CH2C CH2 CH3 D CH3CH CCH3 CH349 / 55
Question 212: The alkane CH3CH2CH(CH3)2 undergoes free radical substitution with chlorine. No C–C bonds are broken in this reaction. How many isomeric pr…Question 213: Geraniol and nerol are isomers of each other. geraniol nerol CH3 CH3 C CH2OH C H H2C C H2C C H CH2OH H3C H2C H3C H2C C C C C H3C H H3C H Wh…Question 214: Which compound has the greatest number of stereoisomers? A 2-methylhex-2-ene B 3-methylhex-2-ene C 4-methylhex-2-ene D 5-methylhex-2-eneQuestion 215: Compound X is found in cell walls of some bacteria. Its structural formula is shown. compound X CH3(CH2)17CH=CH(CH2)17CH(OH)CH(CH3)CO2H How…Question 216: Structural isomerism only should be considered when answering this question. How many straight-chain isomers are there with molecular formu…50 / 55
Question 217: Geraniol and nerol are isomers of each other. geraniol nerol CH3 CH3 C CH2OH C H H2C C H2C C H CH2OH H3C H2C H3C H2C C C C C H3C H H3C H Wh…Question 218: Which compound has the greatest number of stereoisomers? A 2-methylhex-2-ene B 3-methylhex-2-ene C 4-methylhex-2-ene D 5-methylhex-2-eneQuestion 219: The diagrams show the structures of two isomeric dicarboxylic acids, X and Y. O O O HO HO OH C H C C C C C C H C H H OH O X Y X can be redu…51 / 55
Question 220: Structural isomerism and stereoisomerism should be considered when answering this question. 2,5-dibromohexane is heated under reflux with e…Question 221: Considering only structural isomers, what is the number of alcohols of each type with the formula C5H12O? primary secondary tertiary A 3 3 …Question 222: Including structural isomers and stereoisomers, how many isomers are there of C2H2Br2? A 2 B 3 C 4 D 5Question 223: Which compound exhibits stereoisomerism? A 1,1-dichloropropene B 2,3-dichloropropene C 1,2-dichloropropane D 1,3-dichloropropaneQuestion 224: Structural and stereoisomerism should be considered when answering this question. How many alcohols with the molecular formula C5H12O give …52 / 55
Question 225: Compound P displays cis/trans isomerism and gives a red-brown precipitate with Fehling’s solution. What is P? C C H CH3 H CH2CHO A C C H CH…Question 226: Structural isomerism and stereoisomerism should be considered when answering this question. How many isomeric esters of methanoic acid can …Question 227: The diagrams show skeletal formulas of some isomers of C6H12O. O 1 2 O O 3 4 O Which statement is correct? A 1 and 3 are chain isomers of e…53 / 55
Question 228: The skeletal formulas of two compounds are shown. progesterone O O testosterone OH O Which statements about progesterone and testosterone a…Question 229: The structure of disodium cromoglycate is shown. disodium cromoglycate OH O OCH2 CH CH2O O NaO2C O O CO2Na How many chiral centres are ther…54 / 55
Question 230: The diagrams show skeletal formulas of some isomers of C6H12O. O 1 2 O O 3 4 O Which statement is correct? A 1 and 3 are chain isomers of e…55 / 55

Mark scheme230 answers

Answers below. Sit the paper first if you are practising.

Pastlit

Chemistry 9701 · Isomerism: structural isomerism and stereoisomerism — Paper 1

A Level · topical answer key — answer key (teacher use)

Question

Answer

Marks

1B1
2B1
3B1
4B1
5A1
6D1
7C1
8B1
9B1
10C1
11A1
12D1
13D1
14D1
15C1
16D1
17A1
18A1
19C1
20B1
21D1
22B1
23D1
24C1
25D1
26D1
27C1
28C1
29D1
30D1
31C1
32B1
33B1
34B1
35C1
36A1
37D1
38B1
39B1
40C1
41D1
42B1
43—1
44—1
45D1
46B1
47C1
48A1
49B1
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Pastlit

Chemistry 9701 · Isomerism: structural isomerism and stereoisomerism — Paper 1

A Level · topical answer key — answer key (teacher use)

Question

Answer

Marks

50C1
51A1
52D1
53C1
54D1
55C1
56B1
57B1
58D1
59D1
60B1
61B1
62D1
63B1
64B1
65B1
66C1
67C1
68A1
69B1
70C1
71D1
72C1
73A1
74C1
75C1
76C1
77C1
78C1
79C1
80B1
81C1
82A1
83A1
84C1
85A1
86—1
87—1
88B1
89D1
90A1
91D1
92C1
93B1
94B1
95B1
96D1
97C1
98C1
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Pastlit

Chemistry 9701 · Isomerism: structural isomerism and stereoisomerism — Paper 1

A Level · topical answer key — answer key (teacher use)

Question

Answer

Marks

99C1
100D1
101C1
102A1
103B1
104A1
105C1
106C1
107A1
108B1
109A1
110D1
111C1
112B1
113B1
114B1
115A1
116C1
117D1
118A1
119C1
120C1
121B1
122A1
123A1
124C1
125A1
126A1
127C1
128A1
129C1
130C1
131D1
132A1
133C1
134A1
135D1
136B1
137C1
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140D1
141D1
142A1
143B1
144B1
145D1
146C1
147C1
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Pastlit

Chemistry 9701 · Isomerism: structural isomerism and stereoisomerism — Paper 1

A Level · topical answer key — answer key (teacher use)

Question

Answer

Marks

148A1
149B1
150C1
151C1
152B1
153B1
154D1
155D1
156C1
157B1
158D1
159A1
160D1
161D1
162C1
163D1
164C1
165B1
166A1
167B1
168B1
169D1
170D1
171B1
172C1
173C1
174A1
175B1
176D1
177D1
178B1
179C1
180C1
181C1
182A1
183C1
184B1
185B1
186C1
187C1
188D1
189D1
190C1
191B1
192C1
193C1
194D1
195A1
196D1
4 / 5

Pastlit

Chemistry 9701 · Isomerism: structural isomerism and stereoisomerism — Paper 1

A Level · topical answer key — answer key (teacher use)

Question

Answer

Marks

197D1
198C1
199C1
200A1
201B1
202C1
203C1
204C1
205B1
206B1
207A1
208B1
209D1
210C1
211B1
212C1
213B1
214C1
215D1
216A1
217B1
218C1
219A1
220C1
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223C1
224C1
225D1
226D1
227B1
228D1
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Another paper, or another topic

Paper
Paper 1230 questionsPaper 2questions comingPaper 4questions coming

All of An introduction to AS Level organic chemistry →

Questions as text

Q1 · The diagram shows the structure of vitamin C 9701/11 Oct/Nov 2005

19 The diagram shows the structure of vitamin C. HO OH C C O C CH CH CH2OH O OH How many chiral centres are there in one molecule?

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2005

Q2 · What is the number of isomers of C2H2Cl2 including cis-trans isomers? 9701/11 Oct/Nov 2005

20 What is the number of isomers of C2H2Cl2 including cis-trans isomers? A 2 B 3 C 4 D 5

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2005

Q3 · The sex-attractant of the house-fly is muscalure, with the following formula 9701/11 Oct/Nov 2005

40 The sex-attractant of the house-fly is muscalure, with the following formula. CH3(CH2)7CH = CH(CH2)12CH3 Which statements about muscalure are correct? 1 It will decolourise aqueous bromine. 2 It will be oxidised by cold aqueous alkaline KMnO4 to give a diol. 3 It will be optically active.

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2005

Q4 · Warfarin is used as a rat poison 9701/11 May/June 2006

21 Warfarin is used as a rat poison. O O C C C CH CH2 C CH3 OH O warfarin How many chiral centres are present in the warfarin molecule? A 0 B 1 C 2 D 3

1 marks

Answer: B

This question in 9701/11 May/June 2006

Q5 · The structures below show isomers of C6H12 9701/11 May/June 2006

22 The structures below show isomers of C6H12. 1 2 3 4 CH3 CH3 CH3 C2H5 C2H5 H C2H5 CH3 C C C C C C C C H C2H5 H CH3 CH3 CH3 H CH3 In which pair are the members cis-trans isomers of each other? A 1 and 2 B 1 and 3 C 1 and 4 D 2 and 4

1 marks

Answer: A

This question in 9701/11 May/June 2006

Q6 · In which pairs are the members stereoisomers of each other? 9701/11 May/June 2006

37 In which pairs are the members stereoisomers of each other? 1 CH3 CH3 C C Br Br H Cl Cl H 2 CH3 Br Br CH3 C C C C H H H H 3 CH3 Br CH3 H C C C C H Cl Br Cl

1 marks

Answer: D

This question in 9701/11 May/June 2006

Q7 · What is the total number of different chloroethanes, formula C2H6-nCln, where n can be… 9701/11 Oct/Nov 2006

21 What is the total number of different chloroethanes, formula C2H6-nCln, where n can be any integer from 1 to 4? A 4 B 6 C 7 D 8

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2006

Q8 · Which alkene could exist in cis and trans forms? 9701/11 Oct/Nov 2006

23 Which alkene could exist in cis and trans forms? A CH3CH2CH2CH CH2 B CH3CH2CH CHCH3 C CH3CH2C CH2 CH3 D CH3CH CCH3 CH3

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2006

Q9 · Which molecules, each with a linear carbon chain, can have an optically active isomer? 9701/11 Oct/Nov 2007

19 Which molecules, each with a linear carbon chain, can have an optically active isomer? I II III IV C3H6BrI C3H4BrI C3H6I2 C3H4Br2 A I and II only B I, II and III only C II and III only D I, II and IV only

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2007

Q10 · In which pair do the isomers have identical boiling points? 9701/11 Oct/Nov 2007

20 In which pair do the isomers have identical boiling points? A CH3CH2CH2CH2OH and (CH3)2CHCH2OH B CH3(CH2)4CH3 and (CH3)2CHCH(CH3)2 CH3 CH3 C H C and C H Cl CH2Cl Cl H C Cl 2 CH3 H CH3 CH3 D C C and C C H CH3 H H

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2007

Q11 · Trichloroethene is widely used as a dry-cleaning agent 9701/11 May/June 2008

21 Trichloroethene is widely used as a dry-cleaning agent. H Cl \ 4 C=C Ve C Cl With which of the following does trichloroethene react to give a chiral product? A Br B HCl C NaCN(aq) D NaOH(aq)

1 marks

Answer: A

This question in 9701/11 May/June 2008

Q12 · Sorbitol is a naturally-occurring compound with a sweet taste 9701/11 Oct/Nov 2008

20 Sorbitol is a naturally-occurring compound with a sweet taste. It is often used as a substitute for sucrose by the food industry. The diagram shows its structure. H H C O H H C O H H O C H H C O H H C O H H C O H H How many chiral centres are present in sorbitol? A 1 B 2 C 3 D 4

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2008

Q13 · Which hydrocarbon can form a monochloro-substitution derivative which shows both… 9701/11 Oct/Nov 2008

22 Which hydrocarbon can form a monochloro-substitution derivative which shows both chirality and cis-trans isomerism? A CH3CH=CH2 B (CH3)2C=CH2 C CH3CH=C(CH3)2 D CH3CH=CHCH2CH3

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2008

Q14 · In recent years a number of athletes have been banned from sports because of their… 9701/11 May/June 2009

19 In recent years a number of athletes have been banned from sports because of their illegal use of synthetic testosterone, a naturally occurring hormone in the body. OH CH3 CH3 O testosterone How many chiral centres are present in a testosterone molecule? A 1 B 2 C 3 D 6

1 marks

Answer: D

This question in 9701/11 May/June 2009

Q15 · The compound known as ‘gamma-linolenic acid’ is found in significant amounts in the seeds… 9701/11 May/June 2009

20 The compound known as ‘gamma-linolenic acid’ is found in significant amounts in the seeds of the Evening Primrose plant. There is evidence that the compound may help patients with diabetes. CH3(CH2)4CH=CHCH2CH=CHCH2CH=CH(CH2)4CO2H gamma-linolenic acid How many cis-trans isomers does gamma-linolenic acid have? A 3 B 6 C 8 D 12

1 marks

Answer: C

This question in 9701/11 May/June 2009

Q16 · The drug cortisone has the formula shown 9701/11 Oct/Nov 2009

20 The drug cortisone has the formula shown. CH2OH CO CH3 OH O CH3 O In addition to those chiral centres marked by an asterisk (*), how many other chiral centres are present in the cortisone molecule? A 0 B 1 C 2 D 3

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2009

Q17 · The presence of 11-cis retinal, C20H28O, in cells in the eye is important for vision 9701/11 Oct/Nov 2009

21 The presence of 11-cis retinal, C20H28O, in cells in the eye is important for vision. The structure of retinal includes an aldehyde group, a cyclohexene ring and a long aliphatic side chain, in which a carbon-carbon double bond exists between carbons numbered 11 and 12. Which pair of statements about 11-cis retinal could be correct? arrangement around total number of the adjacent carbons >C=C< double bonds 11 and 12 R1 R2 A 5 C C H H R1 H B 5 C C H R2 R1 R2 C 6 C C H H R1 H D 6 C C H R2

1 marks

Answer: A

This question in 9701/11 Oct/Nov 2009

Q18 · What is the least number of carbon atoms in a non-cyclic alkane molecule that has a… 9701/11 Oct/Nov 2009

22 What is the least number of carbon atoms in a non-cyclic alkane molecule that has a chiral centre? A 7 B 8 C 9 D 10

1 marks

Answer: A

This question in 9701/11 Oct/Nov 2009

Q19 · When heated with chlorine, the hydrocarbon 2,2-dimethylbutane undergoes free radical… 9701/11 May/June 2010

21 When heated with chlorine, the hydrocarbon 2,2-dimethylbutane undergoes free radical substitution. In a propagation step the free radical X• is formed. CH3 CH3CH2 C CH3 + Cl → X + HCl ● ● CH3 How many different forms of X• are possible? A 1 B 2 C 3 D 4

1 marks

Answer: C

This question in 9701/11 May/June 2010

Q20 · Which isomer of C4H10O forms three alkenes on dehydration? 9701/11 May/June 2010

29 Which isomer of C4H10O forms three alkenes on dehydration? A butan-1-ol B butan-2-ol C 2-methylpropan-1-ol D 2-methylpropan-2-ol

1 marks

Answer: B

This question in 9701/11 May/June 2010

Q21 · Which compound exhibits both cis-trans and optical isomerism? 9701/11 May/June 2010

30 Which compound exhibits both cis-trans and optical isomerism? A CH3CH=CHCH2CH3 B CH3CHBrCH=CH2 C CH3CBr=CBrCH3 D CH3CH2CHBrCH=CHBr

1 marks

Answer: D

This question in 9701/11 May/June 2010

Q22 · Which isomer of C4H10O forms three alkenes on dehydration? 9701/12 May/June 2010

27 Which isomer of C4H10O forms three alkenes on dehydration? A butan-1-ol B butan-2-ol C 2-methylpropan-1-ol D 2-methylpropan-2-ol

1 marks

Answer: B

This question in 9701/12 May/June 2010

Q23 · Which compound exhibits both cis-trans and optical isomerism? 9701/12 May/June 2010

28 Which compound exhibits both cis-trans and optical isomerism? A CH3CH=CHCH2CH3 B CH3CHBrCH=CH2 C CH3CBr=CBrCH3 D CH3CH2CHBrCH=CHBr

1 marks

Answer: D

This question in 9701/12 May/June 2010

Q24 · When heated with chlorine, the hydrocarbon 2,2-dimethylbutane undergoes free radical… 9701/13 May/June 2010

23 When heated with chlorine, the hydrocarbon 2,2-dimethylbutane undergoes free radical substitution. In a propagation step the free radical X• is formed. CH3 CH3CH2 C CH3 + Cl → X + HCl ● ● CH3 How many different forms of X• are possible? A 1 B 2 C 3 D 4

1 marks

Answer: C

This question in 9701/13 May/June 2010

Q25 · Which compound exhibits both cis-trans and optical isomerism? 9701/13 May/June 2010

26 Which compound exhibits both cis-trans and optical isomerism? A CH3CH=CHCH2CH3 B CH3CHBrCH=CH2 C CH3CBr=CBrCH3 D CH3CH2CHBrCH=CHBr

1 marks

Answer: D

This question in 9701/13 May/June 2010

Q26 · Lactic acid occurs naturally, for example in sour milk 9701/11 Oct/Nov 2010

26 Lactic acid occurs naturally, for example in sour milk. H H O O H C C C H H O H lactic acid What is a property of lactic acid? A It decolourises aqueous bromine rapidly. B It is insoluble in water. C It reduces Fehling’s reagent. D Two molecules react with each other in the presence of a strong acid.

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2010

Q27 · The compound 2-methylpropene, C4H8, is a monomer used in the production of synthetic… 9701/11 Oct/Nov 2010

29 The compound 2-methylpropene, C4H8, is a monomer used in the production of synthetic rubber. H CH3 C C H CH3 In addition to 2-methylpropene there are x other isomers of C4H8, structural or otherwise, which contain a double bond. What is the value of x? A 1 B 2 C 3 D 4

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2010

Q28 · How many structural isomers are there of trichloropropane, C3H5Cl 3? 9701/12 Oct/Nov 2010

20 How many structural isomers are there of trichloropropane, C3H5Cl 3? A 3 B 4 C 5 D 6

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2010

Q29 · CH3CH2COCH2CH3 reacts with hydrogen cyanide to form a cyanohydrin 9701/12 Oct/Nov 2010

29 CH3CH2COCH2CH3 reacts with hydrogen cyanide to form a cyanohydrin. Which feature applies to the product? A It has one chiral centre. B It is formed by electrophilic addition. C It is formed via a C–OH intermediate. D Its formation requires the use of cyanide ions as a catalyst.

1 marks

Answer: D

This question in 9701/12 Oct/Nov 2010

Q30 · Which of the compounds shown have chiral carbon atoms? 9701/12 Oct/Nov 2010

30 Which of the compounds shown have chiral carbon atoms? 1 2 3 4 OH O CH3 CH3 CH3 CH3 OH A 1, 2, 3 and 4 B 1 and 4 only C 2 and 3 only D 2, 3 and 4 only

1 marks

Answer: D

This question in 9701/12 Oct/Nov 2010

Q31 · The compound 2-methylpropene, C4H8, is a monomer used in the production of synthetic… 9701/13 Oct/Nov 2010

29 The compound 2-methylpropene, C4H8, is a monomer used in the production of synthetic rubber. H CH3 C C H CH3 In addition to 2-methylpropene there are x other isomers of C4H8, structural or otherwise, which contain a double bond. What is the value of x? A 1 B 2 C 3 D 4

1 marks

Answer: C

This question in 9701/13 Oct/Nov 2010

Q32 · Pentanol, C5H11OH, has four structural isomers that are primary alcohols 9701/11 May/June 2011

23 Pentanol, C5H11OH, has four structural isomers that are primary alcohols. How many of these primary alcohols contain a chiral carbon atom? A 0 B 1 C 2 D 3

1 marks

Answer: B

This question in 9701/11 May/June 2011

Q33 · The diagram shows the structure of the naturally-occurring molecule cholesterol 9701/11 May/June 2011

24 The diagram shows the structure of the naturally-occurring molecule cholesterol. H3C CH3 H CH3 H H H HO cholesterol Student X claimed that the seventeen carbon atoms in the four rings all lie in the same plane. Student Y claimed that this molecule displays cis-trans isomerism at the C=C double bond. Which of the students are correct? A both X and Y B neither X nor Y C X only D Y only

1 marks

Answer: B

This question in 9701/11 May/June 2011

Q34 · Which isomer of C6H13OH gives the greatest number of different alkenes when it is… 9701/11 May/June 2011

25 Which isomer of C6H13OH gives the greatest number of different alkenes when it is dehydrated? A B CH3 CH3 CH CH CH2OH CH3 CH2 CH2 CH CH2 CH3 CH3 OH C D CH3 CH3 CH3 CH2 C CH2 CH3 CH3 C CH2 CH2OH OH CH3

1 marks

Answer: B

This question in 9701/11 May/June 2011

Q35 · Which alkenes, on reaction with steam at 600 K and 6 x 106 Pa pressure in the presence of… 9701/11 May/June 2011

38 Which alkenes, on reaction with steam at 600 K and 6 x 106 Pa pressure in the presence of a phosphoric acid catalyst, could produce an alcohol containing a chiral carbon atom? 1 (CH3)2C=CH2 2 CH3CH=CHCH3 3 CH3CH2CH=CH2

1 marks

Answer: C

This question in 9701/11 May/June 2011

Q36 · Which compound does not show cis-trans isomerism? 9701/12 May/June 2011

24 Which compound does not show cis-trans isomerism? A 2-methylpent-2-ene B 3-methylpent-2-ene C 3,4-dimethylhex-3-ene D pent-2-ene

1 marks

Answer: A

This question in 9701/12 May/June 2011

Q37 · How many isomers with the formula C5H10 have structures that involve π bonding? 9701/12 May/June 2011

26 How many isomers with the formula C5H10 have structures that involve π bonding? A 3 B 4 C 5 D 6

1 marks

Answer: D

This question in 9701/12 May/June 2011

Q38 · Pentanol, C5H11OH, has four structural isomers that are primary alcohols 9701/13 May/June 2011

25 Pentanol, C5H11OH, has four structural isomers that are primary alcohols. How many of these primary alcohols contain a chiral carbon atom? A 0 B 1 C 2 D 3

1 marks

Answer: B

This question in 9701/13 May/June 2011

Q39 · The diagram shows the structure of the naturally-occurring molecule cholesterol 9701/13 May/June 2011

27 The diagram shows the structure of the naturally-occurring molecule cholesterol. H3C CH3 H CH3 H H H HO cholesterol Student X claimed that the seventeen carbon atoms in the four rings all lie in the same plane. Student Y claimed that this molecule displays cis-trans isomerism at the C=C double bond. Which of the students are correct? A both X and Y B neither X nor Y C X only D Y only

1 marks

Answer: B

This question in 9701/13 May/June 2011

Q40 · Which alkenes, on reaction with steam at 600 K and 6 x 106 Pa pressure in the presence of… 9701/13 May/June 2011

37 Which alkenes, on reaction with steam at 600 K and 6 x 106 Pa pressure in the presence of a phosphoric acid catalyst, could produce an alcohol containing a chiral carbon atom? 1 (CH3)2C=CH2 2 CH3CH=CHCH3 3 CH3CH2CH=CH2

1 marks

Answer: C

This question in 9701/13 May/June 2011

Q41 · A reaction between chlorine and propane in ultraviolet light produces two isomeric… 9701/11 Oct/Nov 2011

27 A reaction between chlorine and propane in ultraviolet light produces two isomeric monochloropropanes, C3H7Cl, as products. Which information about this reaction is correct? expected ratio of type of bond fission 1-chloropropane to in initiation step 2-chloropropane produced A heterolytic 1 : 1 B heterolytic 3 : 1 C homolytic 1 : 1 D homolytic 3 : 1

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2011

Q42 · Disaccharides, C12H22O11, are important in the human diet 9701/11 Oct/Nov 2011

37 Disaccharides, C12H22O11, are important in the human diet. For example, sucrose is found in pastries and lactose occurs in milk products. Both of these compounds can be hydrolysed. sucrose + H2O → CH2OH(CHOH)4CHO + CH2OH(CHOH)3COCH2OH glucose fructose lactose + H2O → CH2OH(CHOH)4CHO + CH2OH(CHOH)4CHO glucose galactose Which statements about these hydrolysis products are correct? 1 Glucose and fructose have structural isomers. 2 Glucose and galactose are optical isomers. 3 Glucose and galactose are ketones.

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2011

Q43 · The use of sucrose in food processing depends in part on osmotic pressure, symbol Π 9701/12 Oct/Nov 2011

9 The use of sucrose in food processing depends in part on osmotic pressure, symbol Π. In dilute solution, Π varies with concentration in a similar way to gas behaviour. The equation Π V = nRT can be used, where n is the number of moles of solute molecules contained in volume V at temperature T. The number of moles of solvent molecules should be ignored. Under aqueous acidic conditions sucrose is hydrolysed. C12H22O11 + H2O → CH2OH(CHOH)4CHO + CH2OH(CHOH)3COCH2OH sucrose glucose fructose What can be deduced from this hydrolysis equation? the osmotic pressure glucose and fructose are A decreases optical isomers B decreases structural isomers C increases optical isomers D increases structural isomers

1 marks

This question in 9701/12 Oct/Nov 2011

Q44 · The molecule shown is optically active 9701/12 Oct/Nov 2011

27 The molecule shown is optically active. Cl H Cl H H Cl C C C C C Cl H H H H Cl C H H How many chiral carbon atoms are present in this molecule? A 1 B 2 C 3 D 4

1 marks

This question in 9701/12 Oct/Nov 2011

Q45 · A reaction between chlorine and propane in ultraviolet light produces two isomeric… 9701/13 Oct/Nov 2011

28 A reaction between chlorine and propane in ultraviolet light produces two isomeric monochloropropanes, C3H7Cl, as products. Which information about this reaction is correct? expected ratio of type of bond fission 1-chloropropane to in initiation step 2-chloropropane produced A heterolytic 1 : 1 B heterolytic 3 : 1 C homolytic 1 : 1 D homolytic 3 : 1

1 marks

Answer: D

This question in 9701/13 Oct/Nov 2011

Q46 · Disaccharides, C12H22O11, are important in the human diet 9701/13 Oct/Nov 2011

39 Disaccharides, C12H22O11, are important in the human diet. For example, sucrose is found in pastries and lactose occurs in milk products. Both of these compounds can be hydrolysed. sucrose + H2O → CH2OH(CHOH)4CHO + CH2OH(CHOH)3COCH2OH glucose fructose lactose + H2O → CH2OH(CHOH)4CHO + CH2OH(CHOH)4CHO glucose galactose Which statements about these hydrolysis products are correct? 1 Glucose and fructose have structural isomers. 2 Glucose and galactose are optical isomers. 3 Glucose and galactose are ketones.

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2011

Q47 · How many isomeric esters have the molecular formula C4H8O2? 9701/11 May/June 2012

24 How many isomeric esters have the molecular formula C4H8O2? A 2 B 3 C 4 D 5

1 marks

Answer: C

This question in 9701/11 May/June 2012

Q48 · What are the same for a pair of optical isomers? 9701/12 May/June 2012

38 What are the same for a pair of optical isomers? 1 their empirical formula 2 their functional groups 3 their structural formula

1 marks

Answer: A

This question in 9701/12 May/June 2012

Q49 · Compound C is used in textile and leather processing 9701/13 May/June 2012

22 Compound C is used in textile and leather processing. O O C CH2 compound C H2C C O O Which starting material(s), on gentle heating with a few drops of concentrated sulfuric acid, generates compound C? A CH3COOH only B HOCH2COOH only C CH3COOCH2COOH only D CH3COOH mixed with HOCH2COOH

1 marks

Answer: B

This question in 9701/13 May/June 2012

Q50 · How many isomeric esters have the molecular formula C4H8O2? 9701/13 May/June 2012

23 How many isomeric esters have the molecular formula C4H8O2? A 2 B 3 C 4 D 5

1 marks

Answer: C

This question in 9701/13 May/June 2012

Q51 · Which compound, on reaction with hydrogen cyanide, produces a compound with a chiral… 9701/13 May/June 2012

26 Which compound, on reaction with hydrogen cyanide, produces a compound with a chiral centre? A CH3CHO B CH3CH2COCH2CH3 C CH3CO2CH3 D HCHO

1 marks

Answer: A

This question in 9701/13 May/June 2012

Q52 · An alkene has the formula CH3CH=CR CH2CH3 and does not possess cis-trans isomers 9701/11 Oct/Nov 2012

21 An alkene has the formula CH3CH=CR CH2CH3 and does not possess cis-trans isomers. What is R ? A H B Cl C CH3 D C2H5

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2012

Q53 · The cracking of a single hydrocarbon molecule, CnH2n+2, produces two hydrocarbon… 9701/11 Oct/Nov 2012

23 The cracking of a single hydrocarbon molecule, CnH2n+2, produces two hydrocarbon molecules only. Each hydrocarbon product contains the same number of carbon atoms in one molecule. Each hydrocarbon product has non-cyclic structural isomers. What is the value of n? A 4 B 6 C 8 D 9

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2012

Q54 · An alkene has the formula CH3CH=CR CH2CH3 and does not possess cis-trans isomers 9701/12 Oct/Nov 2012

21 An alkene has the formula CH3CH=CR CH2CH3 and does not possess cis-trans isomers. What is R ? A H B Cl C CH3 D C2H5

1 marks

Answer: D

This question in 9701/12 Oct/Nov 2012

Q55 · The cracking of a single hydrocarbon molecule, CnH2n+2, produces two hydrocarbon… 9701/12 Oct/Nov 2012

23 The cracking of a single hydrocarbon molecule, CnH2n+2, produces two hydrocarbon molecules only. Each hydrocarbon product contains the same number of carbon atoms in one molecule. Each hydrocarbon product has non-cyclic structural isomers. What is the value of n? A 4 B 6 C 8 D 9

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2012

Q56 · The following compounds are found in the seaweed Asparagopsis taxiformis 9701/11 May/June 2013

20 The following compounds are found in the seaweed Asparagopsis taxiformis. Which compound could show both cis-trans isomerism and optical isomerism? A B C D Cl Cl O Br Cl H H H Br Br Br C Br C C C Br C Br C C Br C C Cl C C I C C Br H I H Cl H Br H

1 marks

Answer: B

This question in 9701/11 May/June 2013

Q57 · Some vegetable oils contain ‘trans fats’ that are associated with undesirable increases… 9701/11 May/June 2013

30 Some vegetable oils contain ‘trans fats’ that are associated with undesirable increases in the amount of cholesterol in the blood. In the diagrams below, R1 and R2 are different hydrocarbon chains. Which diagram correctly illustrates an optically active ‘trans fat’? A B H R1CO2CH2 H R1CO2CH2 CH3(CH2)6C C(CH2)7CO2CH CH3(CH2)6C C(CH2)7CO2CH H R1CO2CH2 H R2CO2CH2 C D H H R1CO2CH2 H H R1CO2CH2 CH3(CH2)6C C(CH2)7CO2CH CH3(CH2)6C C(CH2)7CO2CH R1CO2CH2 R2CO2CH2

1 marks

Answer: B

This question in 9701/11 May/June 2013

Q58 · How many isomers, including structural and stereoisomers, with the formula C4H8 have… 9701/13 May/June 2013

22 How many isomers, including structural and stereoisomers, with the formula C4H8 have structures that involve π bonding? A 1 B 2 C 3 D 4

1 marks

Answer: D

This question in 9701/13 May/June 2013

Q59 · How many isomeric esters, including structural isomers and stereoisomers, can be made… 9701/13 May/June 2013

29 How many isomeric esters, including structural isomers and stereoisomers, can be made with the molecular formula C5H10O2, if methanoic acid is one of the two reactants used? A 2 B 3 C 4 D 5

1 marks

Answer: D

This question in 9701/13 May/June 2013

Q60 · Which compound exhibits stereoisomerism? 9701/11 Oct/Nov 2013

23 Which compound exhibits stereoisomerism? A CH3CHCl CH3 B CH3CHCl CH2Cl C CH3CCl 2CH3 D CH2Cl CH2CH2Cl

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2013

Q61 · What are the only structures formed when butan-2-ol is heated with concentrated H2SO4? 9701/11 Oct/Nov 2013

25 What are the only structures formed when butan-2-ol is heated with concentrated H2SO4? CH3CH2 H CH3 H A C C C C H H H CH3 CH3 CH3 CH3 H H H B C C C C C C H H H CH3 CH3CH2 H H H H H C C C C C CH3CH2 H CH3 CH3 CH3 H CH3CH2 H H H D C C C C C C CH3 H H H CH3 CH3

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2013

Q62 · The compounds below are treated with hydrogen cyanide 9701/11 Oct/Nov 2013

40 The compounds below are treated with hydrogen cyanide. Which compounds react and produce a molecule containing a chiral centre? 1 butanal 2 pentan-3-one 3 2-chlorobutane

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2013

Q63 · Which compound exhibits stereoisomerism? 9701/12 Oct/Nov 2013

23 Which compound exhibits stereoisomerism? A CH3CHCl CH3 B CH3CHCl CH2Cl C CH3CCl 2CH3 D CH2Cl CH2CH2Cl

1 marks

Answer: B

This question in 9701/12 Oct/Nov 2013

Q64 · What are the only structures formed when butan-2-ol is heated with concentrated H2SO4? 9701/12 Oct/Nov 2013

25 What are the only structures formed when butan-2-ol is heated with concentrated H2SO4? CH3CH2 H CH3 H A C C C C H H H CH3 CH3 CH3 CH3 H H H B C C C C C C H H H CH3 CH3CH2 H H H H H C C C C C CH3CH2 H CH3 CH3 CH3 H CH3CH2 H H H D C C C C C C CH3 H H H CH3 CH3

1 marks

Answer: B

This question in 9701/12 Oct/Nov 2013

Q65 · Including structural and stereoisomers, how many isomers are there of C2H2Br2? 9701/13 Oct/Nov 2013

21 Including structural and stereoisomers, how many isomers are there of C2H2Br2? A 2 B 3 C 4 D 5

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2013

Q66 · Including structural and stereoisomers, how many isomeric products are produced when… 9701/13 Oct/Nov 2013

24 Including structural and stereoisomers, how many isomeric products are produced when alcoholic KOH reacts with 2-chlorobutane? A 1 B 2 C 3 D 4

1 marks

Answer: C

This question in 9701/13 Oct/Nov 2013

Q67 · An alcohol with molecular formula CnH2n+1OH has a chiral carbon atom but does not react… 9701/13 Oct/Nov 2013

27 An alcohol with molecular formula CnH2n+1OH has a chiral carbon atom but does not react with hot, acidified K2Cr2O7. What is the smallest possible value for n ? A 5 B 6 C 7 D 8

1 marks

Answer: C

This question in 9701/13 Oct/Nov 2013

Q68 · The reaction of ethanal, CH3CHO, with HCN to form a cyanohydrin is catalysed by NaCN 9701/13 Oct/Nov 2013

38 The reaction of ethanal, CH3CHO, with HCN to form a cyanohydrin is catalysed by NaCN. What are features of the intermediate of this reaction? 1 It is chiral. 2 It has a single negative charge on one of its atoms. 3 It is a nucleophile.

1 marks

Answer: A

This question in 9701/13 Oct/Nov 2013

Q69 · The structural formulae of two compounds are shown below 9701/13 Oct/Nov 2013

40 The structural formulae of two compounds are shown below. O O CH3CH2CH2CH2CH2C CH3CH2CH2CH2CH2OC OH H Which statements about these compounds are correct? 1 The two compounds are structural isomers of each other. 2 The empirical formula of both compounds is C3H6O. 3 Both compounds are carboxylic acids.

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2013

Q70 · There are three structural isomers with the formula C5H12 9701/11 May/June 2014

24 There are three structural isomers with the formula C5H12. Which formulae correctly represent these three structural isomers? A CH3CH2CH2CH2CH3 CH3CH2CHCH3CH3 CH3CH3CCH3CH3 B CH3CH2CH2CH2CH3 CH3CH2(CH)CH3CH3 C(CH3)4 C CH3CH2CH2CH2CH3 CH3CH(CH3)CH2CH3 CH3C(CH3)2CH3 D CH3CH2CH2CH2CH3 CH3CH(CH3)CH2CH3 CH3CH2CH(CH3)CH3

1 marks

Answer: C

This question in 9701/11 May/June 2014

Q71 · CH3CH2COCH2CH3 reacts with hydrogen cyanide to form an organic product called a… 9701/11 May/June 2014

25 CH3CH2COCH2CH3 reacts with hydrogen cyanide to form an organic product called a cyanohydrin. Which feature applies to the cyanohydrin product? A It has one chiral centre. B It is formed by electrophilic addition. C It is formed via an intermediate which contains the C–OH group. D Its formation requires the use of cyanide ions as a catalyst.

1 marks

Answer: D

This question in 9701/11 May/June 2014

Q72 · How many geometrical (cis-trans) isomers are there of hex-2,4-diene, CH3CH=CHCH=CHCH3? 9701/11 May/June 2014

29 How many geometrical (cis-trans) isomers are there of hex-2,4-diene, CH3CH=CHCH=CHCH3? A none; hex-2,4-diene does not show geometric isomerism B 2 C 3 D 4

1 marks

Answer: C

This question in 9701/11 May/June 2014

Q73 · Which alcohol has a chiral centre and can be oxidised to a ketone? 9701/12 May/June 2014

22 Which alcohol has a chiral centre and can be oxidised to a ketone? A pentan-2-ol B pentan-3-ol C 3-methylhexan-1-ol D 3-methylhexan-3-ol

1 marks

Answer: A

This question in 9701/12 May/June 2014

Q74 · Methylpropan-1-ol and butan-1-ol are structural isomers 9701/11 Oct/Nov 2014

9 Methylpropan-1-ol and butan-1-ol are structural isomers. Methylpropan-1-ol has a lower boiling point. Which statement explains why the boiling point of methylpropan-1-ol is lower than that of butan-1-ol? A Methylpropan-1-ol cannot form hydrogen bonds. B Methylpropan-1-ol has weaker covalent bonds than butan-1-ol. C Methylpropan-1-ol has weaker van der Waals’ forces than butan-1-ol. D Methylpropan-1-ol molecules have more surface area than butan-1-ol molecules.

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2014

Q75 · Considering only structural isomers, what is the number of alcohols of each type with the… 9701/11 Oct/Nov 2014

23 Considering only structural isomers, what is the number of alcohols of each type with the formula C5H12O? primary secondary tertiary A 3 3 2 B 4 2 2 C 4 3 1 D 5 2 1

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2014

Q76 · Methylpropan-1-ol and butan-1-ol are structural isomers 9701/12 Oct/Nov 2014

9 Methylpropan-1-ol and butan-1-ol are structural isomers. Methylpropan-1-ol has a lower boiling point. Which statement explains why the boiling point of methylpropan-1-ol is lower than that of butan-1-ol? A Methylpropan-1-ol cannot form hydrogen bonds. B Methylpropan-1-ol has weaker covalent bonds than butan-1-ol. C Methylpropan-1-ol has weaker van der Waals’ forces than butan-1-ol. D Methylpropan-1-ol molecules have more surface area than butan-1-ol molecules.

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2014

Q77 · Considering only structural isomers, what is the number of alcohols of each type with the… 9701/12 Oct/Nov 2014

23 Considering only structural isomers, what is the number of alcohols of each type with the formula C5H12O? primary secondary tertiary A 3 3 2 B 4 2 2 C 4 3 1 D 5 2 1

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2014

Q78 · In this question, structural isomerism and stereoisomerism should be considered 9701/13 Oct/Nov 2014

20 In this question, structural isomerism and stereoisomerism should be considered. How many isomeric aldehydes have the formula C5H10O? A 3 B 4 C 5 D 6

1 marks

Answer: C

This question in 9701/13 Oct/Nov 2014

Q79 · The compound known as ‘gamma-linolenic acid’ is found in the seeds of the evening… 9701/13 Oct/Nov 2014

25 The compound known as ‘gamma-linolenic acid’ is found in the seeds of the evening primrose plant. CH3(CH2)4CH=CHCH2CH=CHCH2CH=CH(CH2)4CO2H gamma-linolenic acid How many cis-trans isomers are there with this structural formula? A 3 B 6 C 8 D 12

1 marks

Answer: C

This question in 9701/13 Oct/Nov 2014

Q80 · The diagram shows the structure of the naturally-occurring molecule cholesterol 9701/13 Oct/Nov 2014

29 The diagram shows the structure of the naturally-occurring molecule cholesterol. H3C CH3 H CH3 H H H HO cholesterol Student X stated that the seventeen carbon atoms in the four rings all lie in the same plane. Student Y stated that this molecule displays cis-trans isomerism at the C = C double bond. Which of the students are correct? A both X and Y B neither X nor Y C X only D Y only

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2014

Q81 · Methyl butanoate, C5H10O2, is an ester used in the food industry to give products the… 9701/13 Oct/Nov 2014

30 Methyl butanoate, C5H10O2, is an ester used in the food industry to give products the flavour of apples. O H H H H C C C C H H C O H H H H methyl butanoate Including methyl butanoate, how many structural isomers are there of C5H10O2 that are esters? A 6 B 8 C 9 D 10

1 marks

Answer: C

This question in 9701/13 Oct/Nov 2014

Q82 · Propanal will react with hydrogen cyanide to form 2-hydroxybutanenitrile 9701/13 Oct/Nov 2014

40 Propanal will react with hydrogen cyanide to form 2-hydroxybutanenitrile. A suitable catalyst for this reaction is sodium cyanide. NaCN CH3CH2CHO + HCN CH3CH2CH(OH)CN Which statements about the reaction of propanal with hydrogen cyanide are correct? 1 The sodium cyanide provides a stronger nucleophile than HCN. 2 The reaction mechanism involves two steps. 3 The product of the reaction has a chiral carbon atom.

1 marks

Answer: A

This question in 9701/13 Oct/Nov 2014

Q83 · In 1869 Ladenburg suggested a structure for benzene, C6H6, in which one hydrogen atom is… 9701/11 May/June 2015

28 In 1869 Ladenburg suggested a structure for benzene, C6H6, in which one hydrogen atom is attached to each carbon atom. CH HC CH CH HC CH Ladenburg structure A compound C6H4Cl 2 could be formed with the same carbon skeleton as the Ladenburg structure. How many structural isomers would this compound have? A 3 B 4 C 5 D 6

1 marks

Answer: A

This question in 9701/11 May/June 2015

Q84 · The diagram shows the structure of an alkene molecule 9701/11 May/June 2015

37 The diagram shows the structure of an alkene molecule. CH3 CH3 CH3 C C H C C H H H CH3 Which statements about this molecule are correct? 1 All the carbon atoms are in the same plane. 2 It has geometrical isomers. 3 It is optically active.

1 marks

Answer: C

This question in 9701/11 May/June 2015

Q85 · Which statements about 2-methylbutan-1-ol are correct? 9701/12 May/June 2015

38 Which statements about 2-methylbutan-1-ol are correct? 1 It can give HCl (g) on reaction with PCl 5. 2 It can be oxidised to give an aldehyde. 3 It exists in two optically active forms.

1 marks

Answer: A

This question in 9701/12 May/June 2015

Q86 · Which compound shows optical isomerism? 9701/12 Oct/Nov 2015

21 Which compound shows optical isomerism? A 2-chloropropane B 1,2-dichloropropane C 1,3-dichloropropane D 2,2-dichloropropane

1 marks

This question in 9701/12 Oct/Nov 2015

Q87 · Compound Q is obtained by adding H2O across the double bond in compound P 9701/12 Oct/Nov 2015

37 Compound Q is obtained by adding H2O across the double bond in compound P. OH P Q Which statements about these two compounds are correct? 1 P shows cis-trans isomerism. 2 Q contains two chiral centres. 3 Q is a tertiary alcohol.

1 marks

This question in 9701/12 Oct/Nov 2015

Q88 · Geraniol and nerol are compounds found in some flower fragrances 9701/12 Feb/March 2016

21 Geraniol and nerol are compounds found in some flower fragrances. They are isomers of each other. CH3 CH3 C CH2OH C H H2C C H2C C H CH2OH H3C H2C H3C H2C C C C C H3C H H3C H geraniol nerol Which type of isomerism is shown here? A chain B geometrical (cis-trans) C optical D positional

1 marks

Answer: B

This question in 9701/12 Feb/March 2016

Q89 · The diagrams show two different compounds 9701/11 May/June 2016

20 The diagrams show two different compounds. O O 1 2 What is ● the total number of structural isomers, including compound 2, that could be formed by adding a second methyl group to the ring of compound 1, ● the number of π electrons in each compound? number of number of isomers π electrons A 3 2 B 3 4 C 5 2 D 5 4

1 marks

Answer: D

This question in 9701/11 May/June 2016

Q90 · Geranyl ethanoate is present in ginger and cocoa, and is used in shampoos and soaps as a… 9701/11 May/June 2016

30 Geranyl ethanoate is present in ginger and cocoa, and is used in shampoos and soaps as a perfume. It reacts with an excess of bromine in an organic solvent to give X, a bromo-derivative. O Br2 O bromo-derivative geranyl ethanoate X Including geranyl ethanoate, how many cis-trans isomers are there of geranyl ethanoate, and how many chiral centres are there in X? chiral centres cis-trans isomers in X A 2 3 B 2 4 C 4 3 D 4 4

1 marks

Answer: A

This question in 9701/11 May/June 2016

Q91 · How many isomeric esters, including structural isomers and stereoisomers, can be made… 9701/12 May/June 2016

29 How many isomeric esters, including structural isomers and stereoisomers, can be made with the molecular formula C5H10O2, if methanoic acid is one of the two reactants used? A 2 B 3 C 4 D 5

1 marks

Answer: D

This question in 9701/12 May/June 2016

Q92 · The diagram shows the structure of 1,3-butadiene 9701/13 May/June 2016

21 The diagram shows the structure of 1,3-butadiene. H H C C H H C C H H 1,3-butadiene The addition reaction between 1,3-butadiene and two molecules of hydrogen bromide can produce three structurally isomeric products. How many of these products have at least one chiral centre? A 0 B 1 C 2 D 3

1 marks

Answer: C

This question in 9701/13 May/June 2016

Q93 · The structural formulae of two compounds are shown below 9701/13 May/June 2016

40 The structural formulae of two compounds are shown below. O O CH3CH2CH2CH2CH2C CH3CH2CH2CH2CH2OC OH H Which statements about these compounds are correct? 1 The two compounds are structural isomers of each other. 2 The empirical formula of both compounds is C3H6O. 3 Both compounds are carboxylic acids.

1 marks

Answer: B

This question in 9701/13 May/June 2016

Q94 · In 1865 Kekulé suggested a ring structure for benzene, C6H6, in which a hydrogen atom is… 9701/11 Oct/Nov 2016

20 In 1865 Kekulé suggested a ring structure for benzene, C6H6, in which a hydrogen atom is attached to each carbon atom. H H C H C C C C H C H H Kekulé structure In this structure all of the bonds remain in the places shown. Assuming this is the structure of benzene, how many isomers of dichlorobenzene, C6H4Cl 2, would exist? A 3 B 4 C 5 D 6

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2016

Q95 · In 1865 Kekulé suggested a ring structure for benzene, C6H6, in which a hydrogen atom is… 9701/13 Oct/Nov 2016

20 In 1865 Kekulé suggested a ring structure for benzene, C6H6, in which a hydrogen atom is attached to each carbon atom. H H C H C C C C H C H H Kekulé structure In this structure all of the bonds remain in the places shown. Assuming this is the structure of benzene, how many isomers of dichlorobenzene, C6H4Cl 2, would exist? A 3 B 4 C 5 D 6

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2016

Q96 · Geraniol and linalool are compounds found in some flower fragrances 9701/12 May/June 2017

21 Geraniol and linalool are compounds found in some flower fragrances. CH3 CH3 HO C CH2OH C H2C C H2C C H H2C H H2C CH2 CH CH C C H3C CH3 H3C CH3 geraniol linalool Which statement is correct? A They are chain isomers of each other. B They are geometrical isomers of each other. C They are optical isomers of each other. D They are positional isomers of each other.

1 marks

Answer: D

This question in 9701/12 May/June 2017

Q97 · Structural isomerism and stereoisomerism should be considered when answering this question 9701/13 May/June 2017

20 Structural isomerism and stereoisomerism should be considered when answering this question. Which formula identifies a single substance? A CH3CHCl CH2CHO B CH3CHCHCH3 C CH2Cl CH2CHCl 2 D C4H10

1 marks

Answer: C

This question in 9701/13 May/June 2017

Q98 · Structural isomerism and stereoisomerism should be considered when answering this question 9701/13 May/June 2017

21 Structural isomerism and stereoisomerism should be considered when answering this question. If a molecule contains two non-identical chiral carbon atoms, four optical isomers exist. How many isomers are there with ● molecular formula C7H14O and ● a five-membered ring and ● a tertiary alcohol group? A 4 B 5 C 9 D 13

1 marks

Answer: C

This question in 9701/13 May/June 2017

Q99 · How many esters with the molecular formula C5H10O2 can be made by reacting a primary… 9701/13 May/June 2017

30 How many esters with the molecular formula C5H10O2 can be made by reacting a primary alcohol with a carboxylic acid? A 4 B 5 C 6 D 8

1 marks

Answer: C

This question in 9701/13 May/June 2017

Q100 · Which compounds, on heating with ethanolic NaOH, produce more than one product with… 9701/13 May/June 2017

38 Which compounds, on heating with ethanolic NaOH, produce more than one product with molecular formula C4H8? 1 2-bromobutane 2 2-bromo-2-methylpropane 3 1-bromo-2-methylpropane

1 marks

Answer: D

This question in 9701/13 May/June 2017

Q101 · The structural formula of compound Q is shown 9701/11 Oct/Nov 2017

20 The structural formula of compound Q is shown. O Q How many stereoisomers exist with this structural formula? A 1 B 2 C 4 D 8

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2017

Q102 · What is the name of compound X? 9701/11 Oct/Nov 2017

21 What is the name of compound X? OH compound X A trans-2-hydroxyhex-3-ene B trans-2-hydroxyhexene C trans-5-hydroxyhex-3-ene D trans-5-hydroxyhexene

1 marks

Answer: A

This question in 9701/11 Oct/Nov 2017

Q103 · In which molecules do all the carbon atoms lie in the same plane? 9701/11 Oct/Nov 2017

37 In which molecules do all the carbon atoms lie in the same plane? 1 2,3-dimethylbut-2-ene 2 propane 3 cyclohexane

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2017

Q104 · The reaction of ethanal, CH3CHO, with HCN to form 2-hydroxypropanenitrile is catalysed by… 9701/11 Oct/Nov 2017

40 The reaction of ethanal, CH3CHO, with HCN to form 2-hydroxypropanenitrile is catalysed by NaCN. What are features of the intermediate of this reaction? 1 It is chiral. 2 It has a single negative charge on one of its atoms. 3 It is a nucleophile.

1 marks

Answer: A

This question in 9701/11 Oct/Nov 2017

Q105 · Which compound does not exhibit stereoisomerism? 9701/12 Oct/Nov 2017

20 Which compound does not exhibit stereoisomerism? A CH3CHCl CH2CHO B CH3CHCHCH3 C CH2Cl CH2CCl 2H D CHCl CHCl

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2017

Q106 · The structural formula of compound Q is shown 9701/13 Oct/Nov 2017

20 The structural formula of compound Q is shown. O Q How many stereoisomers exist with this structural formula? A 1 B 2 C 4 D 8

1 marks

Answer: C

This question in 9701/13 Oct/Nov 2017

Q107 · What is the name of compound X? 9701/13 Oct/Nov 2017

21 What is the name of compound X? OH compound X A trans-2-hydroxyhex-3-ene B trans-2-hydroxyhexene C trans-5-hydroxyhex-3-ene D trans-5-hydroxyhexene

1 marks

Answer: A

This question in 9701/13 Oct/Nov 2017

Q108 · In which molecules do all the carbon atoms lie in the same plane? 9701/13 Oct/Nov 2017

37 In which molecules do all the carbon atoms lie in the same plane? 1 2,3-dimethylbut-2-ene 2 propane 3 cyclohexane

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2017

Q109 · The reaction of ethanal, CH3CHO, with HCN to form 2-hydroxypropanenitrile is catalysed by… 9701/13 Oct/Nov 2017

40 The reaction of ethanal, CH3CHO, with HCN to form 2-hydroxypropanenitrile is catalysed by NaCN. What are features of the intermediate of this reaction? 1 It is chiral. 2 It has a single negative charge on one of its atoms. 3 It is a nucleophile.

1 marks

Answer: A

This question in 9701/13 Oct/Nov 2017

Q110 · Which types of stereoisomerism are shown by 2,4-dimethylhex-2-ene? 9701/12 Feb/March 2018

20 Which types of stereoisomerism are shown by 2,4-dimethylhex-2-ene? A both cis-trans isomerism and optical isomerism B cis-trans isomerism only C neither cis-trans isomerism nor optical isomerism D optical isomerism only

1 marks

Answer: D

This question in 9701/12 Feb/March 2018

Q111 · Structural isomerism and stereoisomerism should be considered when answering this question 9701/12 Feb/March 2018

24 Structural isomerism and stereoisomerism should be considered when answering this question. The molecular formula of compound X is C5H12O. Compound X: ● reacts with alkaline aqueous iodine ● can be dehydrated to form two alkenes only. What could be the identity of compound X? A CH3CH2CH(CH3)CH2OH B CH3CH2CH(OH)CH2CH3 C (CH3)2CHCH(OH)CH3 D CH3CH2CH2CH(OH)CH3

1 marks

Answer: C

This question in 9701/12 Feb/March 2018

Q112 · Fructose is a sugar with more than one chiral centre 9701/11 May/June 2018

20 Fructose is a sugar with more than one chiral centre. The fructose molecule is shown with X, Y and Z indicating three carbon atoms. OH H C H X C O HO C H H C OH Y H C OH H C H Z OH fructose Which carbon atoms are chiral centres? A X, Y and Z B X and Y only C X only D Y only

1 marks

Answer: B

This question in 9701/11 May/June 2018

Q113 · Which pair of alcohols are isomers of each other? 9701/11 May/June 2018

21 Which pair of alcohols are isomers of each other? A butan-1-ol and 2,2-dimethylpropan-1-ol B butan-2-ol and 2-methylpropan-2-ol C pentan-1-ol and 2-methylpropan-2-ol D propan-2-ol and 2-methylpropan-2-ol

1 marks

Answer: B

This question in 9701/11 May/June 2018

Q114 · Which alcohol can be dehydrated to give two products which are structural isomers of each… 9701/11 May/June 2018

23 Which alcohol can be dehydrated to give two products which are structural isomers of each other? A B C D H H H H H H CH3 H H H H CH3 H C C C C OH H C C C OH H C C C OH H C C OH H H H H H H H H CH3 H H CH3

1 marks

Answer: B

This question in 9701/11 May/June 2018

Q115 · Compound Y is treated with an excess of hydrogen gas in the presence of a nickel catalyst 9701/12 May/June 2018

20 Compound Y is treated with an excess of hydrogen gas in the presence of a nickel catalyst. The product is fully saturated. compound Y What is the number of chiral carbon atoms in the product? A 5 B 6 C 7 D 8

1 marks

Answer: A

This question in 9701/12 May/June 2018

Q116 · Structural isomerism and stereoisomerism should be considered when answering this question 9701/12 May/June 2018

24 Structural isomerism and stereoisomerism should be considered when answering this question. A colourless liquid, C5H11Cl , exists as a mixture of two optical isomers. When heated with sodium hydroxide in ethanol, a mixture of only two alkenes is formed. What could the colourless liquid be? A (CH3CH2)2CHCl B CH3CH2CH2CHCl CH3 C (CH3)2CHCHCl CH3 D CH3CH2CCl (CH3)2

1 marks

Answer: C

This question in 9701/12 May/June 2018

Q117 · Which statement about butanone is correct? 9701/12 May/June 2018

27 Which statement about butanone is correct? A Butanone can be dehydrated by concentrated sulfuric acid to give CH2=CHCH=CH2. B Butanone gives a positive result with Tollens’ reagent. C Butanone reacts with HCN by an electrophilic addition mechanism. D Butanone reacts with NaBH4 to give a chiral product.

1 marks

Answer: D

This question in 9701/12 May/June 2018

Q118 · Which compounds show geometrical (cis-trans) isomerism? 9701/12 May/June 2018

37 Which compounds show geometrical (cis-trans) isomerism? 1 CH3CH=C(CH3)C2H5 2 CH3CH=CHCH2CH2CH3 3 C2H5CH=CHC2H5

1 marks

Answer: A

This question in 9701/12 May/June 2018

Q119 · Molecule G is shown 9701/13 May/June 2018

20 Molecule G is shown. O O G How many chiral centres are present in each molecule of G? A 1 B 2 C 3 D 4

1 marks

Answer: C

This question in 9701/13 May/June 2018

Q120 · Considering only structural isomers, what is the number of alcohols of each type with the… 9701/13 May/June 2018

27 Considering only structural isomers, what is the number of alcohols of each type with the formula C5H12O? primary secondary tertiary A 3 3 2 B 4 2 2 C 4 3 1 D 5 2 1

1 marks

Answer: C

This question in 9701/13 May/June 2018

Q121 · Which compounds, on reaction with NaBH4, form a compound with a chiral carbon atom? 9701/13 May/June 2018

37 Which compounds, on reaction with NaBH4, form a compound with a chiral carbon atom? 1 CH3CH2CH2COCH3 2 CH2CHCOCH2CH3 3 CH3CH2COCH2CH3

1 marks

Answer: B

This question in 9701/13 May/June 2018

Q122 · Compound Y is a straight chain molecule with formula CnH2n+1X 9701/13 May/June 2018

38 Compound Y is a straight chain molecule with formula CnH2n+1X. X is a halogen. The Mr of Y is 137. The halogen atom is on the second carbon atom in the chain. Which statements are correct? 1 Y contains a chiral centre. 2 Y can eliminate HX to form two structurally isomeric alkenes. 3 Y can eliminate HX to form two geometrically isomeric alkenes.

1 marks

Answer: A

This question in 9701/13 May/June 2018

Q123 · X has the molecular formula C5H12O 9701/11 Oct/Nov 2018

21 X has the molecular formula C5H12O. X has a branched carbon skeleton and a secondary alcohol functional group. How many structural isomers fit this description of X? A 1 B 2 C 3 D 4

1 marks

Answer: A

This question in 9701/11 Oct/Nov 2018

Q124 · A new jet fuel has been produced that is a mixture of different structural isomers of… 9701/11 Oct/Nov 2018

22 A new jet fuel has been produced that is a mixture of different structural isomers of compound Q. Q Which skeletal formula represents a structural isomer of Q? A B C D

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2018

Q125 · There are three structural isomers with the formula C5H12 9701/12 Oct/Nov 2018

20 There are three structural isomers with the formula C5H12. Which formulae correctly represent these three structural isomers? A CH3CH2CH2CH2CH3 CH3CH(CH3)CH2CH3 C(CH3)4 B CH3CH2CH2CH2CH3 CH3CH(CH3)CH2CH3 CH3CH2CH(CH3)CH3 C D

1 marks

Answer: A

This question in 9701/12 Oct/Nov 2018

Q126 · X has the molecular formula C5H12O 9701/13 Oct/Nov 2018

21 X has the molecular formula C5H12O. X has a branched carbon skeleton and a secondary alcohol functional group. How many structural isomers fit this description of X? A 1 B 2 C 3 D 4

1 marks

Answer: A

This question in 9701/13 Oct/Nov 2018

Q127 · A new jet fuel has been produced that is a mixture of different structural isomers of… 9701/13 Oct/Nov 2018

22 A new jet fuel has been produced that is a mixture of different structural isomers of compound Q. Q Which skeletal formula represents a structural isomer of Q? A B C D

1 marks

Answer: C

This question in 9701/13 Oct/Nov 2018

Q128 · Which compound shows optical isomerism and gives a positive test with alkaline aqueous… 9701/13 Oct/Nov 2018

27 Which compound shows optical isomerism and gives a positive test with alkaline aqueous iodine? A CH3COCH(OH)CH3 B CH3COCH2CH2OH C HOCH2CH(CH3)CHO D (CH3)2C(OH)CHO

1 marks

Answer: A

This question in 9701/13 Oct/Nov 2018

Q129 · How many structural isomers are there of trichloropropane, C3H5Cl 3? 9701/12 Feb/March 2019

20 How many structural isomers are there of trichloropropane, C3H5Cl 3? A 3 B 4 C 5 D 6

1 marks

Answer: C

This question in 9701/12 Feb/March 2019

Q130 · Structural isomerism and stereoisomerism should be considered when answering this question 9701/12 Feb/March 2019

23 Structural isomerism and stereoisomerism should be considered when answering this question. 2-bromopentane is heated with an excess of ethanolic sodium hydroxide. How many different hydrocarbons are produced? A 1 B 2 C 3 D 4

1 marks

Answer: C

This question in 9701/12 Feb/March 2019

Q131 · The diagrams show two different compounds 9701/11 May/June 2019

20 The diagrams show two different compounds. O O 1 2 What is ● the total number of structural isomers, including compound 2, that could be formed by adding a second methyl group to the ring of compound 1, ● the number of π electrons in each compound? number of number of isomers π electrons A 3 2 B 3 4 C 5 2 D 5 4

1 marks

Answer: D

This question in 9701/11 May/June 2019

Q132 · Which compound has the molecular formula C6H10O? 9701/11 May/June 2019

21 Which compound has the molecular formula C6H10O? A B C D O O O OH

1 marks

Answer: A

This question in 9701/11 May/June 2019

Q133 · Structural isomerism and stereoisomerism should be considered when answering this question 9701/11 May/June 2019

26 Structural isomerism and stereoisomerism should be considered when answering this question. 3-methylhexan-3-ol reacts with hot, concentrated sulfuric acid to form several isomeric compounds with the molecular formula C7H14. 3-methylhexan-3-ol HO How many isomeric compounds could be formed in this reaction? A 3 B 4 C 5 D 6

1 marks

Answer: C

This question in 9701/11 May/June 2019

Q134 · Compound X does not show cis-trans isomerism 9701/12 May/June 2019

21 Compound X does not show cis-trans isomerism. What could be the identity of compound X? A 1,1,2-trichloropropene B 1,2,3-trichloropropene C 1-chlorobut-1-ene D 1-chlorobut-2-ene

1 marks

Answer: A

This question in 9701/12 May/June 2019

Q135 · The diagram shows the repeat unit of an addition polymer 9701/12 May/June 2019

22 The diagram shows the repeat unit of an addition polymer. C2H5 CH3 C C CH3 C2H5 n What is the correct name for the monomer that would form this polymer? A cis-1,2-diethyl-1,2-dimethylethene B cis-2-ethyl-3-methylpent-2-ene C trans-2-ethyl-3-methylpent-2-ene D trans-3,4-dimethylhex-3-ene

1 marks

Answer: D

This question in 9701/12 May/June 2019

Q136 · Structural isomerism and stereoisomerism should be considered when answering this question 9701/13 May/June 2019

26 Structural isomerism and stereoisomerism should be considered when answering this question. Which isomer of C6H13OH gives the greatest number of different alkenes when it is dehydrated? A B CH3 CH3 CH CH CH2OH CH3 CH2 CH2 CH CH2 CH3 CH3 OH C D CH3 CH3 CH3 CH2 C CH2 CH3 CH3 C CH2 CH2OH OH CH3

1 marks

Answer: B

This question in 9701/13 May/June 2019

Q137 · Structural isomerism only should be considered when answering this question 9701/13 May/June 2019

28 Structural isomerism only should be considered when answering this question. A set of isomeric compounds, with molecular formula C5H10O, all react in a 1 : 1 ratio with an excess of HCN by nucleophilic addition. How many isomeric compounds are in the set? A 5 B 6 C 7 D 8

1 marks

Answer: C

This question in 9701/13 May/June 2019

Q138 · Which substance reacts with trichloroethene to give a chiral product? 9701/11 Oct/Nov 2019

20 Which substance reacts with trichloroethene to give a chiral product? A Br2 B HCl C NaCN D NaOH

1 marks

Answer: A

This question in 9701/11 Oct/Nov 2019

Q139 · The structure of tiglic acid is CH3CH=C(CH3)CO2H 9701/11 Oct/Nov 2019

37 The structure of tiglic acid is CH3CH=C(CH3)CO2H. Which statements about the properties of one molecule of this acid are correct? 1 It contains two π bonds. 2 It contains four lone pairs of electrons. 3 It has all its atoms in the same plane.

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2019

Q140 · Structural isomerism and stereoisomerism should be considered when answering this question 9701/12 Oct/Nov 2019

20 Structural isomerism and stereoisomerism should be considered when answering this question. How many isomers with the formula C5H10 have structures that involve π bonding? A 3 B 4 C 5 D 6

1 marks

Answer: D

This question in 9701/12 Oct/Nov 2019

Q141 · Compound X has stereoisomers and forms a precipitate when warmed with Fehling’s reagent 9701/12 Oct/Nov 2019

26 Compound X has stereoisomers and forms a precipitate when warmed with Fehling’s reagent. What could be the structure of compound X? A B C D O O O O

1 marks

Answer: D

This question in 9701/12 Oct/Nov 2019

Q142 · Which substance reacts with trichloroethene to give a chiral product? 9701/13 Oct/Nov 2019

20 Which substance reacts with trichloroethene to give a chiral product? A Br2 B HCl C NaCN D NaOH

1 marks

Answer: A

This question in 9701/13 Oct/Nov 2019

Q143 · Which compounds, on heating with an excess of concentrated sulfuric acid, produce only… 9701/13 Oct/Nov 2019

38 Which compounds, on heating with an excess of concentrated sulfuric acid, produce only one product with molecular formula C7H10? 1 2 3 OH OH OH OH OH OH

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2019

Q144 · Which pair of compounds are functional group isomers of each other? 9701/12 Feb/March 2020

20 Which pair of compounds are functional group isomers of each other? A butan-1-ol and butanal B ethylpropanoate and pentanoic acid C hex-1-ene and hex-2-ene D propylamine and propanenitrile

1 marks

Answer: B

This question in 9701/12 Feb/March 2020

Q145 · Structural isomerism and stereoisomerism should be considered when answering this question 9701/12 Feb/March 2020

25 Structural isomerism and stereoisomerism should be considered when answering this question. How many non-cyclic isomers have the molecular formula C5H10? A 3 B 4 C 5 D 6

1 marks

Answer: D

This question in 9701/12 Feb/March 2020

Q146 · Which statement is correct? 9701/11 May/June 2020

21 Which statement is correct? A 2,2-dimethylpropanoic acid is an isomer of propyl methanoate. B 2-methylbutan-2-ol is an isomer of hexan-3-ol. C 3-methylbutan-2-one is an isomer of pentanal. D 3,3-dimethylbutan-2-one is an isomer of pentan-3-one.

1 marks

Answer: C

This question in 9701/11 May/June 2020

Q147 · But-1-ene and but-2-ene are treated separately with cold, dilute acidified manganate(VII)… 9701/11 May/June 2020

22 But-1-ene and but-2-ene are treated separately with cold, dilute acidified manganate(VII) ions. Four students, W, X, Y and Z, make statements about these alkenes and the diols formed from them. W One diol contains two primary alcohol groups. X One diol contains a primary and a secondary alcohol group. Y One diol contains two secondary alcohol groups. Z Both alkenes exhibit cis-trans isomerism. Which two students are correct? A W and Y B W and Z C X and Y D X and Z

1 marks

Answer: C

This question in 9701/11 May/June 2020

Q148 · A mixture of the three isomers of C2H2Cl 2 is polymerised 9701/11 May/June 2020

40 A mixture of the three isomers of C2H2Cl 2 is polymerised. Which sequences will be seen within the polymer chains? 1 2 3 Cl H H H Cl H C C C C C C Cl Cl Cl Cl H H

1 marks

Answer: A

This question in 9701/11 May/June 2020

Q149 · The structure of damascenone is shown 9701/12 May/June 2020

26 The structure of damascenone is shown. damascenone O Including damascenone, how many stereoisomers exist with this structural formula? A 1 B 2 C 4 D 8

1 marks

Answer: B

This question in 9701/12 May/June 2020

Q150 · How many isomeric esters have the molecular formula C4H8O2? 9701/12 May/June 2020

27 How many isomeric esters have the molecular formula C4H8O2? A 2 B 3 C 4 D 5

1 marks

Answer: C

This question in 9701/12 May/June 2020

Q151 · Structural and stereoisomerism should be considered when answering this question 9701/13 May/June 2020

20 Structural and stereoisomerism should be considered when answering this question. When trans-pent-2-ene reacts with HBr, how many different products can form? A 1 B 2 C 3 D 4

1 marks

Answer: C

This question in 9701/13 May/June 2020

Q152 · Which statement about compound T and compound U is correct? 9701/13 May/June 2020

24 Which statement about compound T and compound U is correct? compound T compound U O O H3C C H C CH2CH2CH3 CH(CH3)CH2CH3 A T and U are stereoisomers. B T can be distinguished from U by the use of alkaline aqueous iodine. C T can be reduced by LiAl H4 but not by NaBH4. D U can be formed by the oxidation of 3-methylbutan-1-ol.

1 marks

Answer: B

This question in 9701/13 May/June 2020

Q153 · Which pairs are structural isomers of each other? 9701/13 May/June 2020

40 Which pairs are structural isomers of each other? 1 CH3CH2CH2CH2CH2CO2H and CH3CH2CH2CO2CH2CH3 2 and 3 CH3CH2CH2CH(OH)CH2CH3 and CH3CH2CH(OH)CH2CH2CH3

1 marks

Answer: B

This question in 9701/13 May/June 2020

Q154 · Structural and stereoisomerism should be considered when answering this question 9701/11 Oct/Nov 2020

20 Structural and stereoisomerism should be considered when answering this question. Compounds X, Y and Z are shown. X Y Z HO HO Cl H H Cl Cl OH How many other isomers of C3H7Cl O are there that are alcohols? A 2 B 3 C 4 D 5

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2020

Q155 · Two students each make a statement about 2-methylbut-1-ene 9701/11 Oct/Nov 2020

21 Two students each make a statement about 2-methylbut-1-ene. Student 1 states that 2-methylbut-1-ene has geometrical isomers. Student 2 states that 2-methylbut-1-ene reacts with HBr in an addition reaction to give 1-bromo-2-methylbutane as the main product. Which students are correct? A both 1 and 2 B 1 only C 2 only D neither 1 nor 2

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2020

Q156 · During the bromination of methane, the free radical CH3• is generated 9701/11 Oct/Nov 2020

38 During the bromination of methane, the free radical CH3• is generated. A possible termination step of this reaction is the formation of C2H6 by the combination of two free radicals. What could be produced in a termination step during the bromination of propane? 1 CH3CH2CH(CH3)CH2CH3 2 CH3CH(CH3)CH(CH3)2 3 CH3CH2CH2CH(CH3)2

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2020

Q157 · The unsaturated hydrocarbon octa-1,3,5,7-tetraene, C8H10, can display geometric isomerism 9701/12 Oct/Nov 2020

20 The unsaturated hydrocarbon octa-1,3,5,7-tetraene, C8H10, can display geometric isomerism. octa-1,3,5,7-tetraene CH2=CHCH=CHCH=CHCH=CH2 How many isomers exist? A 2 B 3 C 4 D 8

1 marks

Answer: B

This question in 9701/12 Oct/Nov 2020

Q158 · How many structural isomers are there of molecular formula C5H10O that give a red… 9701/12 Oct/Nov 2020

27 How many structural isomers are there of molecular formula C5H10O that give a red precipitate with Fehling’s solution? A 1 B 2 C 3 D 4

1 marks

Answer: D

This question in 9701/12 Oct/Nov 2020

Q159 · Which substances have molecular formula C4H8O? 9701/12 Oct/Nov 2020

39 Which substances have molecular formula C4H8O? 1 O 2 O OH 3

1 marks

Answer: A

This question in 9701/12 Oct/Nov 2020

Q160 · Structural and stereoisomerism should be considered when answering this question 9701/13 Oct/Nov 2020

20 Structural and stereoisomerism should be considered when answering this question. Compounds X, Y and Z are shown. X Y Z HO HO Cl H H Cl Cl OH How many other isomers of C3H7Cl O are there that are alcohols? A 2 B 3 C 4 D 5

1 marks

Answer: D

This question in 9701/13 Oct/Nov 2020

Q161 · Two students each make a statement about 2-methylbut-1-ene 9701/13 Oct/Nov 2020

21 Two students each make a statement about 2-methylbut-1-ene. Student 1 states that 2-methylbut-1-ene has geometrical isomers. Student 2 states that 2-methylbut-1-ene reacts with HBr in an addition reaction to give 1-bromo-2-methylbutane as the main product. Which students are correct? A both 1 and 2 B 1 only C 2 only D neither 1 nor 2

1 marks

Answer: D

This question in 9701/13 Oct/Nov 2020

Q162 · During the bromination of methane, the free radical CH3• is generated 9701/13 Oct/Nov 2020

38 During the bromination of methane, the free radical CH3• is generated. A possible termination step of this reaction is the formation of C2H6 by the combination of two free radicals. What could be produced in a termination step during the bromination of propane? 1 CH3CH2CH(CH3)CH2CH3 2 CH3CH(CH3)CH(CH3)2 3 CH3CH2CH2CH(CH3)2

1 marks

Answer: C

This question in 9701/13 Oct/Nov 2020

Q163 · The structures of citric acid and isocitric acid are shown 9701/12 Feb/March 2021

20 The structures of citric acid and isocitric acid are shown. citric acid isocitric acid CH2CO2H CH2CO2H C(OH)CO2H CHCO2H CH2CO2H CH(OH)CO2H How many chiral centres does each acid possess? citric acid isocitric acid A 1 1 B 1 2 C 0 1 D 0 2

1 marks

Answer: D

This question in 9701/12 Feb/March 2021

Q164 · How many tertiary alcohols have the molecular formula C6H14O? 9701/12 Feb/March 2021

21 How many tertiary alcohols have the molecular formula C6H14O? A 1 B 2 C 3 D 4

1 marks

Answer: C

This question in 9701/12 Feb/March 2021

Q165 · Which compound could show both cis-trans isomerism and optical isomerism? 9701/11 May/June 2021

22 Which compound could show both cis-trans isomerism and optical isomerism? A B C D Cl Cl O Br Cl H H H Br Br Br C Br C C C Br C C C Br C C Br C C Cl C C I Br H I H Cl H Br H

1 marks

Answer: B

This question in 9701/11 May/June 2021

Q166 · Alcohol X reacts with concentrated sulfuric acid to produce a mixture of products 9701/12 May/June 2021

26 Alcohol X reacts with concentrated sulfuric acid to produce a mixture of products. Two of the products are structural isomers of each other. What could be X? A hexan-2-ol B pentan-1-ol C pentan-3-ol D propan-2-ol

1 marks

Answer: A

This question in 9701/12 May/June 2021

Q167 · Which compound shows stereoisomerism? 9701/13 May/June 2021

20 Which compound shows stereoisomerism? A 2-methylbut-2-ene B 2-chloropropan-1-ol C difluorochlorobromomethane D pent-1-ene

1 marks

Answer: B

This question in 9701/13 May/June 2021

Q168 · Structural isomerism only should be considered when answering this question 9701/11 Oct/Nov 2021

21 Structural isomerism only should be considered when answering this question. Molecule X contains three C=C double bonds. One mole of X is reacted with three moles of HBr. The carbon skeleton is unchanged. molecule X How many different products are formed? A 3 B 4 C 6 D 8

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2021

Q169 · Structural isomerism and stereoisomerism should be considered when answering this question 9701/11 Oct/Nov 2021

22 Structural isomerism and stereoisomerism should be considered when answering this question. A colourless liquid, C5H11Cl , exists as a mixture of two optical isomers. When heated with sodium hydroxide in ethanol, a mixture of only two alkenes is formed. What could the colourless liquid be? A (CH3CH2)2CHCl B CH3CH2CH2CHCl CH3 C CH3CH2CCl (CH3)2 D (CH3)2CHCHCl CH3

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2021

Q170 · CH3CH2COCH2CH3 reacts with hydrogen cyanide to form an organic product called a… 9701/11 Oct/Nov 2021

26 CH3CH2COCH2CH3 reacts with hydrogen cyanide to form an organic product called a cyanohydrin. Which statement is correct? A The cyanohydrin product has one chiral centre. B The cyanohydrin product is formed by electrophilic addition. C The cyanohydrin product is formed via an intermediate which contains a C–OH group. D The formation of the cyanohydrin product requires the use of cyanide ions as a catalyst.

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2021

Q171 · A diketo acid is a compound with two ketone groups and one carboxylic acid group 9701/11 Oct/Nov 2021

37 A diketo acid is a compound with two ketone groups and one carboxylic acid group. limonene terpinolene Which statements about the reactions of limonene and terpinolene are correct? 1 When reacted with an excess of hydrogen and a nickel catalyst, limonene and terpinolene produce the same compound. 2 An excess of hot concentrated acidified KMnO4 reacts with limonene and with terpinolene to form different diketo acids. 3 The reactions of limonene and terpinolene with an excess of Br2 produce positional isomers with the same number of chiral carbon atoms.

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2021

Q172 · The formula of hydrocortisone acetate is shown 9701/12 Oct/Nov 2021

20 The formula of hydrocortisone acetate is shown. hydrocortisone acetate O CH2OCOCH3 CH3 HO OH CH3 O Which row is correct? number of C atoms number of chiral atoms in one molecule in one molecule A 22 7 B 22 8 C 23 7 D 23 8

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2021

Q173 · Structural and stereoisomerism should be taken into account when answering this question 9701/12 Oct/Nov 2021

22 Structural and stereoisomerism should be taken into account when answering this question. Y is a gaseous hydrocarbon which decolourises aqueous bromine. It contains no rings. 10.0 g of Y occupies a volume of 3.43 dm3 under room conditions. How many isomeric structures are possible for Y? A 4 B 5 C 6 D 7

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2021

Q174 · What is the same for a pair of optical isomers? 9701/12 Oct/Nov 2021

37 What is the same for a pair of optical isomers? 1 their empirical formula 2 their functional groups 3 their structural formula

1 marks

Answer: A

This question in 9701/12 Oct/Nov 2021

Q175 · Structural isomerism only should be considered when answering this question 9701/13 Oct/Nov 2021

21 Structural isomerism only should be considered when answering this question. Molecule X contains three C=C double bonds. One mole of X is reacted with three moles of HBr. The carbon skeleton is unchanged. molecule X How many different products are formed? A 3 B 4 C 6 D 8

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2021

Q176 · Structural isomerism and stereoisomerism should be considered when answering this question 9701/13 Oct/Nov 2021

22 Structural isomerism and stereoisomerism should be considered when answering this question. A colourless liquid, C5H11Cl , exists as a mixture of two optical isomers. When heated with sodium hydroxide in ethanol, a mixture of only two alkenes is formed. What could the colourless liquid be? A (CH3CH2)2CHCl B CH3CH2CH2CHCl CH3 C CH3CH2CCl (CH3)2 D (CH3)2CHCHCl CH3

1 marks

Answer: D

This question in 9701/13 Oct/Nov 2021

Q177 · CH3CH2COCH2CH3 reacts with hydrogen cyanide to form an organic product called a… 9701/13 Oct/Nov 2021

26 CH3CH2COCH2CH3 reacts with hydrogen cyanide to form an organic product called a cyanohydrin. Which statement is correct? A The cyanohydrin product has one chiral centre. B The cyanohydrin product is formed by electrophilic addition. C The cyanohydrin product is formed via an intermediate which contains a C–OH group. D The formation of the cyanohydrin product requires the use of cyanide ions as a catalyst.

1 marks

Answer: D

This question in 9701/13 Oct/Nov 2021

Q178 · A diketo acid is a compound with two ketone groups and one carboxylic acid group 9701/13 Oct/Nov 2021

37 A diketo acid is a compound with two ketone groups and one carboxylic acid group. limonene terpinolene Which statements about the reactions of limonene and terpinolene are correct? 1 When reacted with an excess of hydrogen and a nickel catalyst, limonene and terpinolene produce the same compound. 2 An excess of hot concentrated acidified KMnO4 reacts with limonene and with terpinolene to form different diketo acids. 3 The reactions of limonene and terpinolene with an excess of Br2 produce positional isomers with the same number of chiral carbon atoms.

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2021

Q179 · How many esters have the molecular formula C4H8O2? 9701/11 May/June 2022

28 How many esters have the molecular formula C4H8O2? A 2 B 3 C 4 D 5

1 marks

Answer: C

This question in 9701/11 May/June 2022

Q180 · Structural isomerism and stereoisomerism should be taken into account when answering this… 9701/11 May/June 2022

31 Structural isomerism and stereoisomerism should be taken into account when answering this question. How many isomeric alkenes with formula C5H8 are present in the mixture produced when 1,4-dibromopentane is reacted with NaOH in ethanol? A 1 B 2 C 3 D 4

1 marks

Answer: C

This question in 9701/11 May/June 2022

Q181 · A skeletal formula is shown 9701/12 May/June 2022

26 A skeletal formula is shown. What is the total number of stereoisomers including the one shown? A 4 B 6 C 8 D 16

1 marks

Answer: C

This question in 9701/12 May/June 2022

Q182 · Compound Z, C7H13Br, has two chiral centres 9701/12 May/June 2022

28 Compound Z, C7H13Br, has two chiral centres. A sample of Z contains all four possible optical isomers. This sample of Z reacts with hot ethanolic NaOH to produce a mixture of only three isomers. Two of these isomers are optical isomers of each other. What could be the formula of Z? A B C D Br Br Br Br

1 marks

Answer: A

This question in 9701/12 May/June 2022

Q183 · Structural isomerism and stereoisomerism should be considered when answering this question 9701/13 May/June 2022

29 Structural isomerism and stereoisomerism should be considered when answering this question. Y is a gaseous hydrocarbon which decolourises aqueous bromine. 10.0 g of Y occupies a volume of 3.43 dm3 under room conditions. How many isomeric structures are possible for Y? A 4 B 5 C 6 D 7

1 marks

Answer: C

This question in 9701/13 May/June 2022

Q184 · Structural isomerism only should be considered when answering this question 9701/13 May/June 2022

33 Structural isomerism only should be considered when answering this question. Several compounds with molecular formula C4H8O2 have one carbonyl group and one OH group. How many of these compounds produce yellow crystals with alkaline I2(aq) at room temperature? A 2 B 3 C 4 D 5

1 marks

Answer: B

This question in 9701/13 May/June 2022

Q185 · Which pair of alcohols are isomers of each other? 9701/11 Oct/Nov 2022

26 Which pair of alcohols are isomers of each other? A butan-1-ol and 2,2-dimethylpropan-1-ol B butan-2-ol and 2-methylpropan-2-ol C pentan-1-ol and 2-methylpropan-2-ol D propan-2-ol and 2-methylpropan-2-ol

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2022

Q186 · Structural isomerism and stereoisomerism should be considered when answering this question 9701/11 Oct/Nov 2022

35 Structural isomerism and stereoisomerism should be considered when answering this question. How many isomeric compounds with molecular formula C5H6O4 contain two –CO2H groups and one C=C double bond? A 5 B 6 C 7 D 8

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2022

Q187 · The monomer buta-1,3-diene can undergo addition polymerisation in various ways 9701/11 Oct/Nov 2022

39 The monomer buta-1,3-diene can undergo addition polymerisation in various ways. Two of the polymers that can be made are called cis-poly(buta-1,3-diene) and trans-poly(buta-1,3-diene). In these names cis and trans have their usual meanings. What is the structure of the repeat unit of cis-poly(buta-1,3-diene)? A B C D n n n n

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2022

Q188 · The structure of tartaric acid is shown 9701/12 Oct/Nov 2022

26 The structure of tartaric acid is shown. tartaric acid OH O HO OH O OH Which statements about tartaric acid are correct? 1 A molecule of tartaric acid has more than one chiral centre. 2 The molecular formula of tartaric acid is C4H4O6. 3 One molecule of tartaric acid produces four hydrogen ions in aqueous solution. A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 1 only

1 marks

Answer: D

This question in 9701/12 Oct/Nov 2022

Q189 · Which pair includes a hydrocarbon without a chiral centre? 9701/12 Oct/Nov 2022

28 Which pair includes a hydrocarbon without a chiral centre? A CH3CH2CH2CH(CH3)CH2CH3 CH3CH(CH3)CH(CH3)CH2CH3 B CH3CH2CH2CH(CH2CH3)CH3 CH3CH2CH2CH(CH3)CH2CH3 C CH3CH2CH2CH(CH3)CH2CH3 CH3CH2CH(CH3)CH(CH3)2 D CH3CH(CH2CH3)CH(CH3)CH3 CH3CH(CH3)CH2CH(CH3)2

1 marks

Answer: D

This question in 9701/12 Oct/Nov 2022

Q190 · Structural isomerism and stereoisomerism should be considered when answering this question 9701/12 Oct/Nov 2022

34 Structural isomerism and stereoisomerism should be considered when answering this question. 3-methylhexan-3-ol reacts with hot concentrated sulfuric acid to form several isomeric compounds with the molecular formula C7H14. 3-methylhexan-3-ol HO How many isomeric compounds could be formed in this reaction? A 3 B 4 C 5 D 6

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2022

Q191 · Which pair of alcohols are isomers of each other? 9701/13 Oct/Nov 2022

26 Which pair of alcohols are isomers of each other? A butan-1-ol and 2,2-dimethylpropan-1-ol B butan-2-ol and 2-methylpropan-2-ol C pentan-1-ol and 2-methylpropan-2-ol D propan-2-ol and 2-methylpropan-2-ol

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2022

Q192 · Structural isomerism and stereoisomerism should be considered when answering this question 9701/13 Oct/Nov 2022

35 Structural isomerism and stereoisomerism should be considered when answering this question. How many isomeric compounds with molecular formula C5H6O4 contain two –CO2H groups and one C=C double bond? A 5 B 6 C 7 D 8

1 marks

Answer: C

This question in 9701/13 Oct/Nov 2022

Q193 · The monomer buta-1,3-diene can undergo addition polymerisation in various ways 9701/13 Oct/Nov 2022

39 The monomer buta-1,3-diene can undergo addition polymerisation in various ways. Two of the polymers that can be made are called cis-poly(buta-1,3-diene) and trans-poly(buta-1,3-diene). In these names cis and trans have their usual meanings. What is the structure of the repeat unit of cis-poly(buta-1,3-diene)? A B C D n n n n

1 marks

Answer: C

This question in 9701/13 Oct/Nov 2022

Q194 · Which two formulae correctly represent a pair of structural isomers? 9701/12 Feb/March 2023

25 Which two formulae correctly represent a pair of structural isomers? A CH3CH(CH3)COOH and (CH3)2CHCOOH B CH3CH(COOH)CH3 and (CH3)2CHCOOH C CH3CHCOOH and CH3CH2CH2COOH D CH3CH2CH2COOH and (CH3)2CHCOOH

1 marks

Answer: D

This question in 9701/12 Feb/March 2023

Q195 · Compound X, C7H13Br, reacts with hot alcoholic NaOH to produce two compounds, Y and Z 9701/12 Feb/March 2023

27 Compound X, C7H13Br, reacts with hot alcoholic NaOH to produce two compounds, Y and Z. On reaction with Br2, Y gives a product, C7H12Br2, which exists as a mixture of four optical isomers. On reaction with Br2, Z gives a product, C7H12Br2, which is non-chiral. What could X be? A B C D CH3 Br CH2Br CH3 CH3 Br Br

1 marks

Answer: A

This question in 9701/12 Feb/March 2023

Q196 · Cyclohexene, C6H10, is a hydrocarbon with a six-membered ring of carbon atoms 9701/12 Feb/March 2023

29 Cyclohexene, C6H10, is a hydrocarbon with a six-membered ring of carbon atoms. It has several structural isomers that are straight-chain alkenes. The number of double bonds in each of these molecules is P. What is the shape of the cyclohexene molecule and what is the value of P? shape P A planar 1 B planar 2 C non-planar 1 D non-planar 2

1 marks

Answer: D

This question in 9701/12 Feb/March 2023

Q197 · Structural and stereoisomerism should be considered when answering this question 9701/12 Feb/March 2023

34 Structural and stereoisomerism should be considered when answering this question. P has molecular formula C5H10O. P produces an orange precipitate with 2,4-dinitrophenylhydrazine (2,4-DNPH reagent). How many isomeric structures does P have? A 5 B 6 C 7 D 8

1 marks

Answer: D

This question in 9701/12 Feb/March 2023

Q198 · Structural isomerism and stereoisomerism should be considered when answering this question 9701/13 May/June 2023

27 Structural isomerism and stereoisomerism should be considered when answering this question. 2-bromopentane is heated with an excess of ethanolic sodium hydroxide. How many different hydrocarbons are produced? A 1 B 2 C 3 D 4

1 marks

Answer: C

This question in 9701/13 May/June 2023

Q199 · When 1-methylcyclohexene reacts with Br, the product is X 9701/13 May/June 2023

32 When 1-methylcyclohexene reacts with Br, the product is X. When 1-methylcyclohexene reacts with HBr the major product is Y. Br, HBr xX —— —. Y A Xisamixture of two stereoisomers; Y does not have stereoisomers. Which statement is correct? X is a mixture of two stereoisomers; Y is a mixture of four stereoisomers. X is a mixture of four stereoisomers; Y does not have stereoisomers. Oo OO DW X is a mixture of four stereoisomers; Y is a mixture of four stereoisomers.

1 marks

Answer: C

This question in 9701/13 May/June 2023

Q200 · An unsaturated carboxylic acid reacts with alcohol X to form an ester 9701/13 May/June 2023

37 An unsaturated carboxylic acid reacts with alcohol X to form an ester. The structure of the ester is shown. 2 2 Which geometrical isomer is shown in this ester and to which class of alcohol does X belong? geometrical isomer class of alcohol X A cis secondary B cis tertiary C trans secondary D trans tertiary

1 marks

Answer: A

This question in 9701/13 May/June 2023

Q201 · The compound aspartame is widely used as a sweetener in ‘diet’ soft drinks 9701/11 Oct/Nov 2023

26 The compound aspartame is widely used as a sweetener in ‘diet’ soft drinks. aspartame CH3 O O O HO C6H5 NH O NH2 Aspartame is chiral. (There are no chiral carbon atoms in C6H5.) How many chiral carbon atoms are present in a molecule of aspartame? A 1 B 2 C 3 D 4

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2023

Q202 · Artemisinin is a powerful anti-malarial drug 9701/12 Oct/Nov 2023

27 Artemisinin is a powerful anti-malarial drug. artemisinin CH3 O O CH3 O O O CH3 How many chiral centres are there in each molecule of artemisinin? A 4 B 6 C 7 D 8

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2023

Q203 · How many geometrical (cis/trans) isomers are there of hex-2,4-diene, CH3CH=CHCH=CHCH3? 9701/12 Oct/Nov 2023

29 How many geometrical (cis/trans) isomers are there of hex-2,4-diene, CH3CH=CHCH=CHCH3? A none; hex-2,4-diene does not show geometric isomerism B 2 C 3 D 4

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2023

Q204 · How many esters with the molecular formula C5H10O2 can be made by reacting a primary… 9701/12 Oct/Nov 2023

38 How many esters with the molecular formula C5H10O2 can be made by reacting a primary alcohol with a carboxylic acid? A 4 B 5 C 6 D 8

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2023

Q205 · The compound aspartame is widely used as a sweetener in ‘diet’ soft drinks 9701/13 Oct/Nov 2023

26 The compound aspartame is widely used as a sweetener in ‘diet’ soft drinks. aspartame CH3 O O O HO C6H5 NH O NH2 Aspartame is chiral. (There are no chiral carbon atoms in C6H5.) How many chiral carbon atoms are present in a molecule of aspartame? A 1 B 2 C 3 D 4

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2023

Q206 · The diagram shows the structure of the naturally occurring molecule cholesterol 9701/12 Feb/March 2024

25 The diagram shows the structure of the naturally occurring molecule cholesterol. cholesterol H3C CH3 CH3 HO Student X stated that the 17 carbon atoms in the 4 rings all lie in the same plane. Student Y stated that this molecule displays cis/trans isomerism at the C=C double bond. Which students are correct? A both student X and student Y B neither student X nor student Y C student X only D student Y only

1 marks

Answer: B

This question in 9701/12 Feb/March 2024

Q207 · Structural isomerism only should be considered when answering this question 9701/12 Feb/March 2024

36 Structural isomerism only should be considered when answering this question. How many compounds with molecular formula C5H11Br are primary halogenoalkanes? A 4 B 5 C 7 D 8

1 marks

Answer: A

This question in 9701/12 Feb/March 2024

Q208 · Structural isomerism and stereoisomerism should be taken into account when answering this… 9701/11 May/June 2024

25 Structural isomerism and stereoisomerism should be taken into account when answering this question. The structure of 3-methylcyclobutene is shown. 3-methylcyclobutene A mixture containing all stereoisomers of 3-methylcyclobutene is treated with HBr. This produces a mixture of isomeric bromomethylcyclobutanes. How many stereoisomers does 3-methylcyclobutene have, and how many isomeric bromomethylcyclobutanes are present in the product mixture? 3-methylcyclobutene bromomethylcyclobutanes A 2 4 B 2 6 C 4 4 D 4 8

1 marks

Answer: B

This question in 9701/11 May/June 2024

Q209 · Compound T has the skeletal formula shown 9701/12 May/June 2024

32 Compound T has the skeletal formula shown. compound T Which structure is a structural isomer of compound T? A B C D

1 marks

Answer: D

This question in 9701/12 May/June 2024

Q210 · A sample of pent-2-en-4-ol, C5H10O, contains all the possible stereoisomers of this… 9701/12 May/June 2024

36 A sample of pent-2-en-4-ol, C5H10O, contains all the possible stereoisomers of this compound. How many stereoisomers are there in the sample? A 2 B 3 C 4 D 5

1 marks

Answer: C

This question in 9701/12 May/June 2024

Q211 · Which alkene shows geometric isomerism? 9701/13 May/June 2024

25 Which alkene shows geometric isomerism? A CH3CH2CH2CH CH2 B CH3CH2CH CHCH3 C CH3CH2C CH2 CH3 D CH3CH CCH3 CH3

1 marks

Answer: B

This question in 9701/13 May/June 2024

Q212 · The alkane CH3CH2CH(CH3)2 undergoes free radical substitution with chlorine 9701/13 May/June 2024

27 The alkane CH3CH2CH(CH3)2 undergoes free radical substitution with chlorine. No C–C bonds are broken in this reaction. How many isomeric products, including positional and optical isomers, of molecular formula C5H11Cl can be formed? A 4 B 5 C 6 D 7

1 marks

Answer: C

This question in 9701/13 May/June 2024

Q213 · Geraniol and nerol are isomers of each other 9701/11 Oct/Nov 2024

27 Geraniol and nerol are isomers of each other. geraniol nerol CH3 CH3 C CH2OH C H H2C C H2C C H CH2OH H3C H2C H3C H2C C C C C H3C H H3C H Which type of isomerism is shown here? A chain B geometrical (cis / trans) C optical D positional

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2024

Q214 · Which compound has the greatest number of stereoisomers? 9701/11 Oct/Nov 2024

28 Which compound has the greatest number of stereoisomers? A 2-methylhex-2-ene B 3-methylhex-2-ene C 4-methylhex-2-ene D 5-methylhex-2-ene

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2024

Q215 · Compound X is found in cell walls of some bacteria 9701/12 Oct/Nov 2024

26 Compound X is found in cell walls of some bacteria. Its structural formula is shown. compound X CH3(CH2)17CH=CH(CH2)17CH(OH)CH(CH3)CO2H How many stereoisomers are there with this structural formula? A 2 B 4 C 6 D 8

1 marks

Answer: D

This question in 9701/12 Oct/Nov 2024

Q216 · Structural isomerism only should be considered when answering this question 9701/12 Oct/Nov 2024

27 Structural isomerism only should be considered when answering this question. How many straight-chain isomers are there with molecular formula C4H8Cl 2? A 6 B 7 C 8 D 9

1 marks

Answer: A

This question in 9701/12 Oct/Nov 2024

Q217 · Geraniol and nerol are isomers of each other 9701/13 Oct/Nov 2024

27 Geraniol and nerol are isomers of each other. geraniol nerol CH3 CH3 C CH2OH C H H2C C H2C C H CH2OH H3C H2C H3C H2C C C C C H3C H H3C H Which type of isomerism is shown here? A chain B geometrical (cis / trans) C optical D positional

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2024

Q218 · Which compound has the greatest number of stereoisomers? 9701/13 Oct/Nov 2024

28 Which compound has the greatest number of stereoisomers? A 2-methylhex-2-ene B 3-methylhex-2-ene C 4-methylhex-2-ene D 5-methylhex-2-ene

1 marks

Answer: C

This question in 9701/13 Oct/Nov 2024

Q219 · The diagrams show the structures of two isomeric dicarboxylic acids, X and Y 9701/12 Feb/March 2025

38 The diagrams show the structures of two isomeric dicarboxylic acids, X and Y. O O O HO HO OH C H C C C C C C H C H H OH O X Y X can be reduced to compound P with empirical formula C2H5O. Y can be reduced to compound Q, also with empirical formula C2H5O. Which statement is correct? A X is a cis isomer; compound P and compound Q are identical. B X is a cis isomer; compound P and compound Q are isomers of each other. C X is a trans isomer; compound P and compound Q are identical. D X is a trans isomer; compound P and compound Q are isomers of each other.

1 marks

Answer: A

This question in 9701/12 Feb/March 2025

Q220 · Structural isomerism and stereoisomerism should be considered when answering this question 9701/11 May/June 2025

30 Structural isomerism and stereoisomerism should be considered when answering this question. 2,5-dibromohexane is heated under reflux with ethanolic KOH. How many isomeric compounds are formed with molecular formula C6H10? A 3 B 5 C 6 D 7

1 marks

Answer: C

This question in 9701/11 May/June 2025

Q221 · Considering only structural isomers, what is the number of alcohols of each type with the… 9701/11 May/June 2025

31 Considering only structural isomers, what is the number of alcohols of each type with the formula C5H12O? primary secondary tertiary A 3 3 2 B 4 2 2 C 4 3 1 D 5 2 1

1 marks

Answer: C

This question in 9701/11 May/June 2025

Q222 · Including structural isomers and stereoisomers, how many isomers are there of C2H2Br2? 9701/12 May/June 2025

38 Including structural isomers and stereoisomers, how many isomers are there of C2H2Br2? A 2 B 3 C 4 D 5

1 marks

Answer: B

This question in 9701/12 May/June 2025

Q223 · Which compound exhibits stereoisomerism? 9701/12 May/June 2025

39 Which compound exhibits stereoisomerism? A 1,1-dichloropropene B 2,3-dichloropropene C 1,2-dichloropropane D 1,3-dichloropropane

1 marks

Answer: C

This question in 9701/12 May/June 2025

Q224 · Structural and stereoisomerism should be considered when answering this question 9701/13 May/June 2025

32 Structural and stereoisomerism should be considered when answering this question. How many alcohols with the molecular formula C5H12O give a yellow precipitate with alkaline I2(aq)? A 2 B 3 C 4 D 5

1 marks

Answer: C

This question in 9701/13 May/June 2025

Q225 · Compound P displays cis/trans isomerism and gives a red-brown precipitate with Fehling’s… 9701/13 May/June 2025

37 Compound P displays cis/trans isomerism and gives a red-brown precipitate with Fehling’s solution. What is P? C C H CH3 H CH2CHO A C C H CH3 H COCH3 B C C H CHO H CH3 C C C CHO CH3 H H D

1 marks

Answer: D

This question in 9701/13 May/June 2025

Q226 · Structural isomerism and stereoisomerism should be considered when answering this question 9701/14 May/June 2025

36 Structural isomerism and stereoisomerism should be considered when answering this question. How many isomeric esters of methanoic acid can be made with the molecular formula C5H10O2? A 2 B 3 C 4 D 5

1 marks

Answer: D

This question in 9701/14 May/June 2025

Q227 · The diagrams show skeletal formulas of some isomers of C6H12O 9701/11 Oct/Nov 2025

25 The diagrams show skeletal formulas of some isomers of C6H12O. O 1 2 O O 3 4 O Which statement is correct? A 1 and 3 are chain isomers of each other and positional isomers of each other. B 2 and 3 are functional group isomers of each other and both have a chiral centre. C 1 and 4 are functional group isomers of each other and both have a chiral centre. D 2 and 4 are positional isomers of each other and functional group isomers of each other.

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2025

Q228 · The skeletal formulas of two compounds are shown 9701/11 Oct/Nov 2025

26 The skeletal formulas of two compounds are shown. progesterone O O testosterone OH O Which statements about progesterone and testosterone are correct? A They both contain a ketone group, and they both have geometrical isomers due to the C=C bond. B They have the same molecular formula, and they both have geometrical isomers. C They have the same number of chiral carbons, and they have the same molecular formula. D They have the same number of chiral carbons, and they both contain a ketone group.

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2025

Q229 · The structure of disodium cromoglycate is shown 9701/12 Oct/Nov 2025

26 The structure of disodium cromoglycate is shown. disodium cromoglycate OH O OCH2 CH CH2O O NaO2C O O CO2Na How many chiral centres are there in this molecule? A 0 B 1 C 2 D 3

1 marks

Answer: A

This question in 9701/12 Oct/Nov 2025

Q230 · The diagrams show skeletal formulas of some isomers of C6H12O 9701/13 Oct/Nov 2025

25 The diagrams show skeletal formulas of some isomers of C6H12O. O 1 2 O O 3 4 O Which statement is correct? A 1 and 3 are chain isomers of each other and positional isomers of each other. B 2 and 3 are functional group isomers of each other and both have a chiral centre. C 1 and 4 are functional group isomers of each other and both have a chiral centre. D 2 and 4 are positional isomers of each other and functional group isomers of each other.

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2025