Syllabus Edition

First teaching 2023

First exams 2025

|

Shapes of Organic Molecules; σ & π Bonds (CIE AS Chemistry)

Exam Questions

59 mins16 questions
11 mark

How many pi bonds does a molecule of ethene, C2H4 contain?

  • 0

  • 1

  • 2

  • 3

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21 mark

Which type of bond results from the side-to-side overlap of p orbitals?

  • Sigma (σ) bond

  • Pi (π) bond

  • Covalent bond

  • Ionic bond

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31 mark

How many sigma and pi bonds are present in a double bond?

  sigma bonds pi bonds
A 2 0
B 1 1
C 0 2
D 1 2

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    41 mark

    What is the hybridisation of the carbon atom in methane, CH4?

    • sp

    • sp2 

    • sp3 

    • sp3d

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    51 mark

    Which of the following molecules is a straight-chain hydrocarbon?

    • Benzene

    • Cyclopentane

    • 2-methylpropane 

    • Propane

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    11 mark

    Methyl isocyanate, CH3NCO, is a toxic liquid which is used in the production of adhesives. 

    The sequence of atoms in a methyl isocyanate molecule is H3C—N=C=O.

    What is the approximate angle between the bonds formed by the N atom?

    • 3-1-m-5a

    • 3-1-m-5b

    • 3-1-m-5c

    • 3-1-m-5d

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    21 mark

    A synthetic molecule called N-acetylcysteine is used as an antidote for patients who have ingested too many paracetamol tablets.

    The diagram shows part of the molecule N-acetylcysteine and bond angles have been labelled.

    3-1-cie-ial-chemistry-diagram-q7medium

    Which is the correct size order of bond angles x, y, z from smallest to largest?

    • rightwards arrowrightwards arrow z

    • rightwards arrowrightwards arrow x

    • rightwards arrowrightwards arrow x

    • rightwards arrowrightwards arrow y

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    31 mark

    A student is building a non-cyclic, chiral alkane from a molymod kit. What is the lowest number of carbon atoms they will need to include in the model? 

    • 6

    • 11

    • 9

    • 7

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    11 mark

    Methacrylate acrylonitrile is an organic molecule that contains carbons that are sp, sp2, and sp3 hybridised. 

    What is the most likely bond angle for carbon that is sp2 hybridised?

    • 105degree

    • 109degree

    • 120degree

    • 180degree

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    21 mark

    The amino acid cysteine performs structural and functional roles within proteins. It is used as a nucleophile in enzymatic reactions and can form disulfide bonds with other cysteine molecules. 

    3-1-h-4

    How many carbon molecules in cysteine are sp2 hybridised?

    • 3

    • 2

    • 1

    • 0

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    31 mark

    Limonene is found in the peel of citrus fruits.

    3-1-cie-ial-chemistry-diagram-q7hard

    How many σ and π bonds are present in this molecule?

     

    σ

    π

    A

    24

    4

    B

    12

    2

    C

    26

    2

    D

    22

    4

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