An introduction to AS Level organic chemistry: past paper questions

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• Question 25May/June 2026, paper 11Multiple choice1 markHas a diagram

  The formula of 11-cis-retinal is ${\text{C}}_{20}{\text{H}}_{28}\text{O}$. The structure of 11-cis-retinal consists of a cyclohexene ring and a long aliphatic side chain ending in an aldehyde group. The long aliphatic side chain contains one or more $\text{C}=\text{C}$ bonds.

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• Question 6Oct/Nov 2025, paper 11Multiple choice1 markHas a diagram

  ${\text{NH}}_3$ and $\text{HCN}$ react together to form ${\text{NH}}_4\text{CN}$, an ionic compound. Which row states the number of coordinate bonds and the number of $\pi$ bonds in one formula unit of ${\text{NH}}_4\text{CN}$?

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• Question 25Oct/Nov 2024, paper 11Multiple choice1 mark

  Ethene reacts with steam in the presence of sulfuric acid. $${\text{C}}_2{\text{H}}_4+{\text{H}}_2\text{O}\to {\text{CH}}_3{\text{CH}}_2\text{OH}$$ Which type of reaction is this?

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• Question 25Oct/Nov 2023, paper 11Multiple choice1 markHas a diagram

  Hexamine is a crystalline solid used as a fuel in portable stoves. The diagram shows its skeletal structure. What is the empirical formula of hexamine?

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• Question 26May/June 2026, paper 11Multiple choice1 mark

  Which compound has the empirical formula ${\text{CH}}_2\text{O}$?

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• Question 25Oct/Nov 2025, paper 11Multiple choice1 markHas a diagram

  The diagrams show skeletal formulas of some isomers of ${\text{C}}_6{\text{H}}_{12}\text{O}$.

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• Question 27Oct/Nov 2024, paper 11Multiple choice1 markHas a diagram

  Geraniol and nerol are isomers of each other. Which type of isomerism is shown here?

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• Question 26Oct/Nov 2023, paper 11Multiple choice1 markHas a diagram

  The compound aspartame is widely used as a sweetener in ‘diet’ soft drinks. Aspartame is chiral. (There are no chiral carbon atoms in ${\mathrm{C}}_6{\mathrm{H}}_5$.) How many chiral carbon atoms are present in a molecule of aspartame?

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• Question 27May/June 2026, paper 11Multiple choice1 markHas a diagram

  The structure of an ether X is shown. The $\text{C}-\text{O}-\text{C}$ group is the functional group in the homologous series of ethers.

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• Question 26Oct/Nov 2025, paper 11Multiple choice1 markHas a diagram

  The skeletal formulas of two compounds are shown. progesterone and testosterone Which statements about progesterone and testosterone are correct?

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• Question 28Oct/Nov 2024, paper 11Multiple choice1 mark

  Which compound has the greatest number of stereoisomers?

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• Question 27Oct/Nov 2023, paper 11Multiple choice1 mark

  How many $\sigma$ and $\pi$ bonds are in the molecule ${\mathrm{H}\mathrm{C}\mathrm{C}\mathrm{C}\mathrm{H}}_2{\mathrm{C}\mathrm{H}}_2\mathrm{C}\mathrm{H}\mathrm{C}({\mathrm{C}\mathrm{H}}_3{)}_2$?

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• Question 31May/June 2026, paper 11Multiple choice1 mark

  Structural isomerism and stereoisomerism should be taken into account when answering this question.

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• Question 5Oct/Nov 2025, paper 12Multiple choice1 markHas a diagram

  The bonding between two atoms of nitrogen in an ${\text{N}}_2$ molecule involves the hybridisation of atomic orbitals to form $\text{sp}$ orbitals. Which row is correct?

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• Question 36Oct/Nov 2024, paper 11Multiple choice1 mark

  Which compound, on reaction with hydrogen cyanide, produces a compound with a chiral centre?

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• Question 6Oct/Nov 2023, paper 12Multiple choice1 mark

  Which feature is present in both ethene and poly(ethene)?

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• Question 32May/June 2026, paper 11Multiple choice1 mark

  Which organic reaction has a nucleophilic substitution mechanism?

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• Question 25Oct/Nov 2025, paper 12Multiple choice1 mark

  Two statements about a molecule of methanal are given. 1 It is planar. 2 It contains three $\sigma$ bonds.

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• Question 25Oct/Nov 2024, paper 12Multiple choice1 markHas a diagram

  The diagram shows the structural formula of a hydrocarbon molecule Q. How many of the carbon atoms in molecule Q are ${\text{sp}}^2$ hybridised?

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• Question 27Oct/Nov 2023, paper 12Multiple choice1 markHas a diagram

  Artemisinin is a powerful anti-malarial drug. How many chiral centres are there in each molecule of artemisinin?

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• Question 6May/June 2026, paper 12Multiple choice1 mark

  Descriptions of some covalent bonds are given. 1 the overlap of two p orbitals 2 the overlap of two sp hybrid orbitals 3 the overlap of two s orbitals Which bonds are present in the hydrogen cyanide molecule, HCN?

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• Question 26Oct/Nov 2025, paper 12Multiple choice1 markHas a diagram

  The structure of disodium cromoglycate is shown. How many chiral centres are there in this molecule?

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• Question 26Oct/Nov 2024, paper 12Multiple choice1 mark

  Compound X is found in cell walls of some bacteria. Its structural formula is shown.

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• Question 28Oct/Nov 2023, paper 12Multiple choice1 markHas a diagram

  Which row shows the correct name and classification of the halogenoalkane shown?

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• Question 25May/June 2026, paper 12Multiple choice1 mark

  What is the least number of carbon atoms in a non-cyclic alkane molecule that has a chiral centre?

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• Question 27Oct/Nov 2024, paper 12Multiple choice1 mark

  Structural isomerism only should be considered when answering this question. How many straight-chain isomers are there with molecular formula ${\mathrm{C}}_4{\mathrm{H}}_8{\mathrm{C}\mathrm{l}}_2$?

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• Question 29Oct/Nov 2023, paper 12Multiple choice1 mark

  How many geometrical (cis/trans) isomers are there of hex-2,4-diene, ${\text{CH}}_3{\text{CH=CHCH=CHCH}}_3$?

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• Question 26May/June 2026, paper 12Multiple choice1 mark

  The first propagation step in the reaction between methane and chlorine is shown. $${\text{CH}}_4+{\text{Cl}}^{\bullet }\to {\text{CH}}_3^{\bullet }+\text{HCl}$$ How many different first propagation steps are possible in the reaction between pentane and chlorine?

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• Question 28Oct/Nov 2024, paper 12Multiple choice1 mark

  What is true of every nucleophile?

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• Question 30Oct/Nov 2023, paper 12Multiple choice1 markHas a diagram

  The structure of compound X is shown. One mole of compound X reacts completely with two moles of hydrogen bromide. What is the structure of the major product of this reaction?

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