Lesson 2A.2

2A.2 Covalent bonding and molecular shapes Quiz: Pearson Edexcel Chemistry, Unit 2

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson 2A.2, Covalent bonding and molecular shapes: 20 multiple choice questions for the Pearson Edexcel Chemistry (9CH0), Unit 2: Bonding and Structure, written with Revision Ninja.

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The 20 questions

  1. What is a covalent bond?

    • The electrostatic attraction between two nuclei and the shared pair of electrons between them
    • The attraction between molecules caused by temporary dipoles that form and disappear very quickly
    • The transfer of electrons from one atom to another, leaving the two atoms as oppositely charged ions
    • The attraction between metal ions and the sea of delocalised electrons that holds a metal together

  2. What is the shape of a methane molecule, CH4?

    • Tetrahedral, with bond angles of 109.5 degrees
    • Linear, with bond angles of 180 degrees
    • Square planar, with bond angles of 90 degrees
    • Trigonal planar, with bond angles of 120 degrees

  3. What is the approximate bond angle in a water molecule?

    • 109.5 degrees
    • 104.5 degrees
    • 180 degrees
    • 120 degrees

  4. What is the shape of an ammonia molecule, NH3?

    • Trigonal pyramidal, with bond angles of about 107 degrees
    • Trigonal planar, with all bond angles of 120 degrees and no lone pairs on the central nitrogen atom
    • Tetrahedral, with bond angles of 109.5 degrees because four electron pairs repel equally
    • Bent, with bond angles of about 104.5 degrees because the lone pairs compress the bonds

  5. What is the shape of a carbon dioxide molecule?

    • Trigonal planar, with bond angles of 120 degrees
    • Linear, with bond angles of 180 degrees
    • Tetrahedral, with bond angles of 109.5 degrees
    • Bent, with bond angles of about 104.5 degrees

  6. What is the shape of a boron trichloride molecule, BCl3?

    • Tetrahedral, with bond angles of 109.5 degrees
    • Trigonal planar, with bond angles of 120 degrees
    • Trigonal pyramidal, with bond angles of 107 degrees
    • Linear, with bond angles of 180 degrees

  7. In the ammonium ion, NH4+, how is the fourth N-H bond formed?

    • Nitrogen donates a lone pair to a hydrogen ion, forming a dative covalent bond
    • Nitrogen loses an electron to the hydrogen ion, which then bonds to the nitrogen through an ionic link
    • Both bonding electrons are shared equally between the nitrogen and hydrogen atoms in the ion
    • Hydrogen donates a pair of electrons to nitrogen, which then accepts them into a new bonding orbital

  8. Which bond is shortest?

    • The double bond in C=C
    • The triple bond in N2
    • The single bond in N-N
    • The single bond in C-C

  9. Which order of electron-pair repulsion is correct?

    • Bonding pair-bonding pair > lone pair-bonding pair > lone pair-lone pair
    • Lone pair-bonding pair > lone pair-lone pair > bonding pair-bonding pair
    • All pairs repel equally regardless of type
    • Lone pair-lone pair > lone pair-bonding pair > bonding pair-bonding pair

  10. What is the shape of a PCl5 molecule?

    • Square planar, because the five chlorine atoms lie in a single flat plane around the phosphorus
    • Octahedral, because six electron pairs surround the central phosphorus atom in the molecule
    • Tetrahedral, because four bonding pairs surround the central phosphorus atom in the molecule
    • Trigonal bipyramidal

  11. What is the shape and bond angle of an SF6 molecule?

    • Tetrahedral, with bond angles of 109.5 degrees
    • Trigonal bipyramidal, with bond angles of 120 degrees
    • Octahedral, with bond angles of 180 degrees
    • Octahedral, with bond angles of 90 degrees

  12. How many lone pairs are on the central oxygen atom of a water molecule?

    • 1
    • 2
    • 4
    • 0

  13. Predict the bond angle in BeCl2.

    • 109.5 degrees
    • 180 degrees
    • 90 degrees
    • 120 degrees

  14. Why is the H-O-H bond angle in water smaller than the H-C-H angle in methane?

    • Hydrogen atoms repel each other more strongly in water than they do in methane molecules
    • Water has double bonds that pull the two hydrogen atoms closer to the central oxygen atom
    • The two lone pairs on oxygen repel more strongly than bonding pairs, compressing the H-O-H angle
    • Oxygen has fewer electrons than carbon, so the bonding pairs in water are drawn closer together

  15. How many shared electron pairs are in a triple covalent bond, as in N2?

    • 3
    • 6
    • 1
    • 2

  16. In Al2Cl6, how many dative (coordinate) bonds are there?

    • 1
    • 4
    • 6
    • 2

  17. How many electron pairs surround the central sulfur atom in SF6?

    • 4
    • 5
    • 8
    • 6

  18. Which species has a bond angle closest to 120 degrees?

    • BCl3
    • NH3, a trigonal pyramid with bond angles of about 107 degrees because of its single lone pair
    • CH4, a tetrahedral molecule with bond angles of about 109.5 degrees between its four bonds
    • H2O, a bent molecule with bond angles of about 104.5 degrees because of its two lone pairs

  19. Predict the shape and bond angle of the NH4+ ion and justify your answer.

    • Tetrahedral, with bond angles of 104.5 degrees, because the lone pairs on nitrogen compress the angle between its bonding pairs
    • Trigonal pyramidal, with bond angles of 107 degrees, because one lone pair remains on the nitrogen atom and pushes the bonds together
    • Tetrahedral, with bond angles of 109.5 degrees, because there are four bonding pairs and no lone pairs around nitrogen
    • Square planar, with bond angles of 90 degrees, because four bonding pairs repel equally and lie in a single plane around nitrogen

  20. A molecule XF5 is trigonal bipyramidal. Which bond angles are present?

    • 109.5 degrees between all atoms, because the five fluorine atoms arrange themselves as a regular tetrahedron around X
    • 180 degrees between the equatorial atoms only, because the equatorial fluorines sit directly opposite one another across X
    • 90 degrees between all atoms, because the five fluorine atoms all lie at right angles to the central atom in the molecule
    • 120 degrees between equatorial atoms and 90 degrees between axial and equatorial atoms, with 180 degrees between axial atoms

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