Transition Metals Practice Questions PDF

1. Which of the following is the *correct* de nition of a transition metal? * A) An element with a partially lled d-orbital in its atomic form. * B) An element that forms at least one stable ion with a partially lled d- orbital. * C) An element in the d-block of the periodic table. * D) An element t...

1. Which of the following is the *correct* de nition of a transition metal? * A) An element with a partially lled d-orbital in its atomic form. * B) An element that forms at least one stable ion with a partially lled d- orbital. * C) An element in the d-block of the periodic table. * D) An element that forms coloured compounds. 2. Which of the following is *not* considered a transition metal? * A) Iron (Fe) * B) Copper (Cu) * C) Zinc (Zn) * D) Cobalt (Co) 3. What is the electronic con guration of a Cu2+ ion? * A) [Ar] 4s2 3d9 * B) [Ar] 4s1 3d10 * C) [Ar] 4s0 3d9 * D) [Ar] 4s0 3d10 4. What is the electronic con guration of Fe? * A) [Ar] 4s2 3d6 * B) [Ar] 4s1 3d7 * C) [Ar] 4s0 3d8 * D) [Ar] 4s2 3d5 5. Why are transition metals able to form complex ions? * A) They have a large atomic radius. * B) They have high electronegativity. * C) They have variable oxidation states and available, partially lled/ empty d-orbitals for bonding. * D) They have low ionisation energies. 6. What is a ligand? * A) A molecule or ion that donates a pair of electrons to a central metal ion to form a coordinate bond. * B) A central metal ion in a complex ion. * C) A counter-ion that balances the charge of a complex ion. * D) A molecule that can act as both an acid and a base. 7. What is a monodentate ligand? fi fi fi fi fi fi * A) A ligand that forms one coordinate bond to the central metal ion. * B) A ligand that forms two coordinate bonds to the central metal ion. * C) A ligand that forms multiple coordinate bonds to the central metal ion. * D) A ligand that cannot form coordinate bonds. 8. Which of the following is a monodentate ligand? * A) H2O * B) C2O42- (oxalate) * C) en (ethylenediamine) * D) EDTA4- 9. What is the coordination number of a complex ion? * A) The total charge of the complex ion. * B) The number of ligands attached to the central metal ion. * C) The number of coordinate bonds formed by the central metal ion. * D) The oxidation state of the central metal ion. 10. What is the shape of a complex ion with a coordination number of 6? * A) Tetrahedral * B) Square planar * C) Octahedral * D) Linear 11. What is the shape of the [CuCl4]2- complex ion? * A) linear * B) Octahedral * C) Square planar * D) Tetrahedral 12. What is the colour of the [Cu(H2O)6]2+ complex ion in aqueous solution? * A) Blue * B) Green * C) Yellow * D) Colourless 13. What is the colour of the [Co(H2O)6]2+ complex ion? * A) Blue * B) Pink  * C) Green * D) Purple 14. What is the colour of Cr3+(aq) ions? * A) Blue * B) Pink * C) Green * D) Purple 15. Why are transition metal complexes often coloured? * A) They absorb all wavelengths of visible light. * B) They re ect all wavelengths of visible light. * C) They absorb speci c wavelengths of visible light, promoting d- orbital electrons, and the remaining wavelengths are transmitted/ re ected. * D) They do not interact with visible light. 16. Why is [Zn(H2O)6]2+ colourless? * A) it absorbs all wavelengths of visible light * B) It has a full d-orbital, so no d-d electron transitions are possible. * C) It has an empty d-orbital, so no d-d electron transitions are possible. * D) It is not a transition metal complex. 17. Which factors affect the colour of a transition metal complex? * A) the metal only * B) the ligand only * C) metal, ligand and coordination number * D) temperature 18. What is the value of Planck's constant (h)? * A) 6.02 x 1023 J s-1 * B) 3.00 x 108 J s-1 * C) 6.63 x 10-34 J s * D) 1.60 x 10-19 J s 19. What is the equation that links the energy difference (ΔE) between d-orbitals and frequency (f) of light? * A) ΔE = hf * B) ΔE = f/h * C) f = ΔE h fl fl fi * D) h = ΔE f 20. How do you calculate the frequency (f) of light, if given the wavelenght (휆)? * A) 휆/c * B) c x 휆 * C) c / 휆 * D) h / 휆 21. In the equation ΔE = hf, what are the units of ΔE? * A) mol.dm-3 * B) s-1 * C) J * D) J mol-1 22. What is a ligand substitution reaction? * A) swapping the central metal in a complex ion * B) A reaction where one ligand in a complex ion is replaced by another ligand. * C) A reaction where the coordination number of a complex ion changes. * D) A reaction where the oxidation state of the central metal ion changes. 23. What is formed when excess concentrated hydrochloric acid is added to an aqueous solution of copper(II) ions? * A) [Cu(H2O)6]2+ * B) [Cu(H2O)4(OH)2] * C) [Cu(NH3)4(H2O)2]2+ * D) [CuCl4]2- 24. What colour change occurs when excess concentrated hydrochloric acid is added to aqueous copper(II) ions? * A) Blue to yellow-green * B) Blue to deep blue * C) Green to blue * D) Blue to colourless 25. What is formed when excess aqueous ammonia is added to an aqueous solution containing [Cu(H2O)6]2+ ions? * A) a pale blue precipitate * B) [CuCl4]2- * C) a deep blue solution of [Cu(NH3)4(H2O)2]2+ * D) [Cu(OH)4]2- 26. What type of reaction occurs when aqueous sodium hydroxide is added dropwise to [Cu(H2O)6]2+? * A) ligand substitution * B) neutralisation * C) acid-base * D) redox 27. Which of the following can act as a heterogeneous catalyst? * A) Fe2+ (aq) * B) V2O5 (s) * C) MnO4- (aq) * D) H+ (aq) 28. In the Contact process, what is the catalyst? * A) Iron (Fe) * B) Vanadium(V) oxide (V2O5) * C) Platinum (Pt) * D) Nickel (Ni) 29. How does a heterogeneous catalyst work? * A) By forming a homogeneous mixture with the reactants. * B) By providing an alternative reaction pathway with a lower activation energy, with reactants adsorbing onto the surface and products desorbing. * C) By increasing the temperature of the reaction. * D) By increasing the pressure of the reaction. Answers and Explanations: 1. B) An element that forms at least one stable ion with a partially lled d- orbital. - This is the precise de nition. fi fi  2. C) Zinc (Zn) - Zn only forms Zn2+ which has a full d-orbital (3d10). 3. C) [Ar] 4s0 3d9 - Electrons are lost from the 4s orbital rst. 4. A) [Ar] 4s2 3d6 - Correct electronic con guration. 5. C) They have variable oxidation states and available, partially lled/ empty d-orbitals for bonding. - This allows for coordinate bond formation. 6. A) A molecule or ion that donates a pair of electrons to a central metal ion to form a coordinate bond. - This is the de nition of a ligand. 7. A) A ligand that forms one coordinate bond to the central metal ion. - "Monodentate" means "one-toothed". 8. A) H2O - Water can donate one lone pair of electrons. 9. C) The number of coordinate bonds formed by the central metal ion. - This is the de nition. Note that it is *not* always the number of ligands. 10. C) Octahedral - Six coordinate bonds are arranged octahedrally. 11. D) Tetrahedral - Due to the larger size of Cl- ligands, the complex is tetrahedral, not square planar 12. A) Blue - [Cu(H2O)6]2+ is a blue solution. 13. B) Pink - correct colour. 14. C) Green - Correct colour 15. C) They absorb speci c wavelengths of visible light, promoting d- orbital electrons, and the remaining wavelengths are transmitted/ re ected. - This is the basis of d-d transitions and colour. 16. B) It has a full d-orbital, so no d-d electron transitions are possible. - A full d-orbital (d10) means no electrons can be promoted. 17. C) metal, ligand and coordination number All of these can affect the fl fi fi fi fi fi fi energy gap between d-orbitals. 18. C) 6.63 x 10-34 J s - This is the correct value. 19. A) ΔE = hf - This equation links energy difference and frequency. 20. C) c / 휆 Correct equation. 21. C) J - Energy is measured in joules. 22. B) A reaction where one ligand in a complex ion is replaced by another ligand. - This is the de nition. 23. D) [CuCl4]2- - The tetrachlorocuprate(II) ion is formed. 24. A) Blue to yellow-green - This is the characteristic colour change. 25. C) a deep blue solution of [Cu(NH3)4(H2O)2]2+ - Ammonia replaces water ligands (partially). 26. C) acid-base Dropwise addition of OH- will form a precipitate of Cu(OH)2. 27. B) V2O5 (s) - This is a solid catalyst used in the Contact process. 28. B) Vanadium(V) oxide (V2O5) - This is the catalyst used in the Contact process. 29. B) By providing an alternative reaction pathway with a lower activation energy, with reactants adsorbing onto the surface and products desorbing. - This describes the mechanism of heterogeneous catalysis. 30. C) When a product of a reaction acts as a catalyst for that reaction. - This is the de nition of autocatalysis. fi fi Powered by pmfm.ai Request Support