Lesson 3.2.5.2

3.2.5.2 Substitution reactions Quiz: AQA Chemistry, Unit 2

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson 3.2.5.2, Substitution reactions: 20 multiple choice questions for the AQA Chemistry (7405), Unit 2: Inorganic chemistry, written with Revision Ninja.

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The 20 questions

  1. Which of these is a monodentate ligand?

    • Water, H2O
    • H2NCH2CH2NH2
    • Ethanedioate ion, C2O4^2-
    • EDTA4-

  2. Which ligand is multidentate?

    • EDTA4-
    • Water, H2O
    • Chloride ion, Cl-
    • Ammonia, NH3

  3. What is the denticity of the ethanedioate ion, C2O4^2-?

    • Monodentate
    • Tridentate
    • Bidentate
    • Hexadentate

  4. Which pair of ligands is similar in size and uncharged?

    • CN- and Cl-
    • NH3 and H2O
    • Cl- and H2O
    • Cl- and NH3

  5. Which metal ion shows exchange of NH3 and H2O without a change in co-ordination number?

    • Co2+ and Cu2+
    • Cu+ only
    • Fe3+ only
    • Ag+ only

  6. Why does substituting water ligands with chloride ligands decrease the co-ordination number?

    • Larger ligand size
    • Higher ligand charge
    • Lower ligand mass
    • Smaller ligand size

  7. Which term describes the substitution of monodentate ligands by multidentate ligands to form a more stable complex?

    • Inductive effect
    • Cis-trans effect
    • Common ion effect
    • Chelate effect

  8. Which molecule, present in haemoglobin, contains a multidentate iron(II) complex that binds oxygen?

    • Cisplatin
    • EDTA
    • Haem
    • Myoglobin

  9. Which ligand is displaced from iron(II) in haemoglobin when carbon monoxide poisoning occurs?

    • Oxygen
    • Water
    • Carbon dioxide
    • Ammonia

  10. Which equation shows the formation of an incompletely substituted complex?

    • [Cu(H2O)6]2+ + 6NH3 -> [Cu(NH3)6]2+ + 6H2O
    • [Cu(H2O)6]2+ + 2NH3 -> [Cu(NH3)2(H2O)4]2+ + 2H2O
    • [Cu(H2O)6]2+ + 4Cl- -> [CuCl4]2- + 6H2O
    • Cu2+ + 2e- -> Cu

  11. How does the co-ordination number of copper change when [Cu(H2O)6]2+ reacts with excess chloride ions?

    • Decreases from 6 to 2
    • Increases from 4 to 6
    • Decreases from 6 to 4
    • Remains at 6

  12. What is the balanced equation for ethanedioate ions displacing water from [Cu(H2O)6]2+? (The ethanedioate is C2O4^2-.)

    • [Cu(H2O)6]2+ + C2O4^2- -> Cu(C2O4) + 6H2O
    • [Cu(H2O)6]2+ + 2C2O4^2- -> [Cu(C2O4)2] + 6H2O
    • [Cu(H2O)6]2+ + C2O4^2- -> [Cu(C2O4)(H2O)4] + 2H2O
    • [Cu(H2O)6]2+ + C2O4^2- -> [Cu(C2O4)2]2+ + 6H2O

  13. Why does ligand substitution with multidentate ligands increase entropy?

    • Fewer free particles
    • Higher activation energy
    • Stronger coordinate bonds
    • More free particles

  14. How many co-ordinate bonds can one EDTA4- ligand form with a central metal ion?

    • Eight
    • Four
    • Two
    • Six

  15. Which thermodynamic term mainly drives the formation of a chelate complex during ligand substitution?

    • Positive entropy change
    • Negative entropy change
    • Endothermic enthalpy change
    • Exothermic enthalpy change

  16. What shape is formed when excess chloride ions substitute water ligands in [Cu(H2O)6]2+?

    • Square planar
    • Linear
    • Octahedral
    • Tetrahedral

  17. What type of bond is formed between oxygen and the iron(II) ion in haemoglobin?

    • Covalent bond
    • Hydrogen bond
    • Ionic bond
    • Co-ordinate bond

  18. A complex with four monodentate ligands and one bidentate ligand has what co-ordination number?

    • 8
    • 6
    • 5
    • 4

  19. What type of ligand is ethane-1,2-diamine (en) in transition metal complexes?

    • Hexadentate
    • Bidentate
    • Tridentate
    • Monodentate

  20. How many co-ordinate bonds can a single ammonia ligand form with a central metal ion?

    • One
    • Two
    • Three
    • Four

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