Shapes of organic molecules; σ and π bonds: past paper questions

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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 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 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 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 36May/June 2026, paper 12Multiple choice1 markHas a diagram

  Ethanenitrile is heated with an excess of sodium hydroxide until the reaction is complete, giving organic compound X. Which row is correct?

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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 26May/June 2024, paper 11Multiple choice1 markHas a diagram

  The diagram shows the structure of X. Which row is correct?

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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 39May/June 2026, paper 12Multiple choice1 mark

  Structural isomerism and stereoisomerism should be considered when answering this question.

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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 33May/June 2024, paper 12Multiple choice1 markHas a diagram

  The diagram shows a simplified structure of coenzyme ${\text{Q}}_{10}$. Which row describes the structure of coenzyme ${\text{Q}}_{10}$ correctly?

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• Question 6May/June 2026, paper 13Multiple choice1 mark

  Some orbital overlaps that occur in molecules are listed.

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• Question 6May/June 2024, paper 13Multiple choice1 markHas a diagram

  A structure for borazole, ${\mathrm{N}}_3{\mathrm{B}}_3{\mathrm{H}}_6$, is shown. Which shape is borazole and how many $\pi$ electrons are there in the structure?

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• Question 7May/June 2023, paper 11Multiple choice1 markHas a diagram

  Histidine is an amino acid. What are the approximate bond angles 1, 2, and 3?

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• Question 26May/June 2026, paper 13Multiple choice1 markHas a diagram

  A student looks at the structure of chloroethene and of poly(chloroethene) and draws two conclusions. 1 The carbon atoms are ${\text{sp}}^3$ hybridised in each substance. 2 Chloroethene and poly(chloroethene) contain chiral carbon atoms.

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• Question 39May/June 2025, paper 11Multiple choice1 mark

  The structural formula of hept-1,4,5-triene is shown. $${\text{CH}}_2{\text{CHCH}}_2{\text{CHCCHCH}}_3$$ How many of the carbon atoms in one molecule of hept-1,4,5-triene are ${\text{sp}}^2$ hybridised?

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• Question 5May/June 2024, paper 21Structured9 marksHas a diagram

  Hydrocarbon molecules contain covalent bonds. Define covalent bond.

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• Question 6May/June 2023, paper 12Multiple choice1 markHas a diagram

  Which statement about the $\text{Cl}-\text{N}=\text{O}$ molecule is correct?

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• Question 8May/June 2025, paper 13Multiple choice1 markHas a diagram

  The structure of a molecule found in food is shown. Four statements about the molecule are listed. 1 This molecule contains only $\sigma$ bonds.

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• Question 4May/June 2024, paper 22Structured15 marksHas a diagram

  $\mathrm{C}{\mathrm{H}}_3(\mathrm{C}{\mathrm{H}}_2{)}_5\mathrm{C}\mathrm{H}\mathrm{B}\mathrm{r}\mathrm{C}{\mathrm{H}}_3$ exists as a pair of stereoisomers. Draw the three-dimensional structures of the two stereoisomers of $\mathrm{C}{\mathrm{H}}_3(\mathrm{C}{\mathrm{H}}_2{)}_5\mathrm{C}\mathrm{H}\mathrm{B}\mathrm{r}\mathrm{C}{\mathrm{H}}_3$.

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• Question 4May/June 2023, paper 21Structured8 marksHas a diagram

  $\mathbf{V}$ is a colourless liquid. Fig. 4.1 $\mathbf{V}$ reacts with an excess of ${\mathrm{L}\mathrm{i}\mathrm{A}\mathrm{l}\mathrm{H}}_4$ to form $\mathbf{W}$. Draw the structure of $\mathbf{W}$ in the box.

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• Question 5May/June 2025, paper 23Structured14 marksHas a diagram

  W is a colourless liquid. [Fig. 5.1] Deduce the empirical formula of W.

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• Question 5May/June 2023, paper 23Structured8 marksHas a diagram

  $\mathbf{Y}$ is formed from $\mathbf{X}$ in a single-step reaction, as shown in Fig. 5.1. Deduce the empirical formula of $\mathbf{Y}$.

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