The Transition Metals 940 Exam Prep Chapter.19 - Chemistry Canada 4e | Complete Test Bank by John A. Olmsted. DOCX document preview.
CHAPTER 19
THE TRANSITION METALS
CHAPTER STUDY OBJECTIVES
1. Predict periodic properties of transition metals.
SKILLS TO MASTER: Naming groups of transition metals; knowing trends in melting point, density, and oxidation states; determining oxidation states in compounds of transition metals
KEY CONCEPTS: Oxidation states of metals play a key role in determining properties of compounds containing these metals.
2. Recognize and name transition metal coordination complexes.
SKILLS TO MASTER: Recognizing and naming some common ligands; drawing cis and trans as well as fac and mer isomers; naming coordination compounds
KEY CONCEPTS: A ligand bonds to a metal or metal cation using its lone pairs of electrons. Linkage isomers occur when a ligand can bond to a metal using either of two donor atoms.
3. Use crystal field theory to explain the colour and magnetic properties of complexes.
SKILLS TO MASTER: Constructing a crystal field energy-level diagram for an octahedral complex; determining the electron configuration of a complex from magnetic properties; determining the value of D from the absorption spectrum of a complex
KEY CONCEPTS: If P > D, a high-spin complex will likely result. The spectrochemical series lists ligands in order of increasing energy-level splitting. For a given ligand, D increases as the oxidation state of the metal increases.
4. Explain the importance of transition metal complexes in biological processes.
KEY CONCEPTS: Many transition metals (V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Mo) are essential for life. Metalloproteins may act as storage or transport agents, enzymes, or redox reagents.
5. Explain the chemistry of essential steps in the production of pure metals from ores.
KEY CONCEPTS: Metallurgy includes separation, conversion, reduction, and refining steps. The starting material is an impure ore, and the end product is pure metal. Separation processes include flotation and leaching. Many sulphide ores are converted to oxides before reduction.
6. Recognize the importance of transition metals in everyday life.
Multiple Choice QUESTIONS
1. What is the correct arrangement of Sc, V, and Cu in order of increasing melting point?
a) Sc, V, Cu
b) Cu, Sc, V
c) Sc, Cu, V
d) V, Sc, Cu
e) Cu, V, Sc
Difficulty: Medium
Learning Objective: Predict periodic properties of transition metals.
Section Reference: 19.1 Overview of the Transition Metals
2. What is the correct arrangement of Cr, Ni, and Zn in order of decreasing density?
a) Cr, Ni, Zn
b) Ni, Cr, Zn
c) Zn, Ni, Cr
d) Zn, Cr, Ni
e) Ni, Zn, Cr
Difficulty: Medium
Learning Objective: Predict periodic properties of transition metals.
Section Reference: 19.1 Overview of the Transition Metals
3. What is the correct arrangement of Pd, Ni, and Pt in order of decreasing density?
a) Pd, Ni, Pt
b) Ni, Pd, Pt
c) Pt, Ni, Pd
d) Pt, Pd, Ni
e) Ni, Pt, Pd
Difficulty: Easy
Learning Objective: Predict periodic properties of transition metals.
Section Reference: 19.1 Overview of the Transition Metals
Feedback: Density decreases as you move up a column in the periodic table as the decrease in volume is less significant than the decrease in mass.
4. What is the correct arrangement of Hf, Ti, and Zr in order of increasing melting point?
a) Hf, Ti, Zr
b) Ti, Zr, Hf
c) Zr, Hf, Ti
d) Hf, Zr, Ti
e) Ti, Hf, Zr
Difficulty: Easy
Learning Objective: Predict periodic properties of transition metals.
Section Reference: 19.1 Overview of the Transition Metals
Feedback: Melting point increases as you move down a column.
5. The transition metals with the electron configurations of 4s23d2 and 5s24d7 are
a) Cr and Ag.
b) Zr and Au.
c) Ti and Rh.
d) Ti and Pd.
e) Sc and Rh.
Difficulty: Medium
Learning Objective: Predict periodic properties of transition metals.
Section Reference: 19.1 Overview of the Transition Metals
6. Which of the following transition metals in the 3d series has the least variability in preferred oxidation number?
a) Mn
b) Cu
c) Cr
d) V
e) Sc
Difficulty: Hard
Learning Objective: Predict periodic properties of transition metals.
Section Reference: 19.1 Overview of the Transition Metals
7. Which of the following transition metals in the 3d series has the most variability in preferred oxidation number?
a) Mn
b) Cu
c) Cr
d) V
e) Sc
Difficulty: Hard
Learning Objective: Predict periodic properties of transition metals.
Section Reference: 19.1 Overview of the Transition Metals
8. The standard reduction potential for aqueous Ag+ is 0.80 V. This value of the reduction potential
a) means silver is easily oxidized.
b) means silver is a good reducing agent.
c) means Ag+ is a good oxidizing agent.
d) is why silver forms oxy-ions.
e) means Ag is easily reduced.
Difficulty: Medium
Learning Objective: Predict periodic properties of transition metals.
Section Reference: 19.1 Overview of the Transition Metals
9. Which transition metal compounds are most likely to found as pure elements?
a) Au, Ag, As
b) Au, Pt, Ir
c) Cu, Zn, Pt
d) Hg, Fe, Pt
e) Hg, Pt, Au
Difficulty: Easy
Learning Objective: Predict periodic properties of transition metals.
Section Reference: 19.1 Overview of the Transition Metals
Feedback: Simple question requires that students recognize symbols for elements and realize that it the Pt group metals that tend to be found as pure elements.
10. Which is the chemical formula for the compound named hexamminecobalt(III) sulphate?
a) [Co(NH3)6][SO4]
b) [Co(NH3)7][SO4]
c) [Co(NH3)6]2[SO3]3
d) [Co(NH3)6][SO4]2
e) [Co(NH3)6]2[SO4]3
Difficulty: Medium
Learning Objective: Recognize and name transition metal coordination complexes.
Section Reference: 19.2 Coordination Complexes
11. What is the oxidation state of rhodium in pentaamminebromorhodium bromide, [Rh(NH3)5Br]Br2?
a) 0
b) +1
c) +2
d) +3
e) –2
Difficulty: Easy
Learning Objective: Recognize and name transition metal coordination complexes.
Section Reference: 19.2 Coordination Complexes
Feedback: Complex cation must have a charge of +2, therefore, Rh must be +3.
12. The complex Fe(C2O4)33- has one unpaired electron. What is the electron configuration of this complex?
(If needed, use the following equation:
Spectrochemical Series I- < Br- < Cl- < F- < OH‑ < H2O< NH3 < en < NO2- < CN- < CO)
a) t2g4eg1
b) t2g5eg1
c) t2g5
d) t2g4eg2
e) t2g3eg2
Difficulty: Medium
Learning Objective: Use crystal field theory to explain the colour and magnetic properties of complexes.
Section Reference: 19.3 Bonding in Coordination Complexes
13. Which of the following has the most unpaired electrons?
(If needed, use the following equation:
Spectrochemical Series I- < Br- < Cl- < F- < OH‑ < H2O< NH3 < en < NO2- < CN- < CO)
a) [NiCl4]2-
b) [IrCl6]3-
c) [Cr(CN)6]3-
d) [Fe(NH3)6]2+
e) [Co(NH3)6]3+
Difficulty: Medium
Learning Objective: Use crystal field theory to explain the colour and magnetic properties of complexes.
Section Reference: 19.3 Bonding in Coordination Complexes
Feedback: Must apply rules associated with ligand field splitting due to nature of metal centre, nature of ligand and geometry. a) 2 unpaired; b) 0 unpaired; c) 3 unpaired; 4) 4 unpaired; 5) 0 unpaired
14. You have two samples, one contains [Cr(CN)6]3- and the second [CrF6]3-. One solution is yellow, the second is green and they were found to have absorbance maxima at 650 and 380 nm. Unfortunately, you forgot to annotate which sample was which. Based on your knowledge which of the below show the correct assignments?
(If needed, use the following equation:
Spectrochemical Series I- < Br- < Cl- < F- < OH‑ < H2O< NH3 < en < NO2- < CN- < CO)
a) [Cr(CN)6]3- : yellow, 650 nm; [CrF6]3- : green, 380 nm
b) [Cr(CN)6]3- : yellow, 380 nm; [CrF6]3- : green, 650 nm
c) [Cr(CN)6]3- : green, 650 nm; [CrF6]3- :yellow, 380 nm
d) [Cr(CN)6]3- : green, 380 nm; [CrF6]3- : yellow, 650 nm
Difficulty: Hard
Learning Objective: Use crystal field theory to explain the colour and magnetic properties of complexes.
Section Reference: 19.3 Bonding in Coordination Complexes
Feedback: Three concepts are required to answer this question correctly. 1) CN- is a high field ligand, F- is a low field ligand thus the CN- complex will absorb higher energy light than will the F- complex. Higher energy light has a shorter wavelength. The solution will appear as the complimentary colour; yellow is complementary to lower wavelength (higher energy) than is green.
15. [Co(NH3)5NO2]Cl2 and [Co(NH3)5ONO]Cl2 are examples of what type of isomer?
(If needed, use the following equation:
Spectrochemical Series I- < Br- < Cl- < F- < OH‑ < H2O< NH3 < en < NO2- < CN- < CO)
a) coordination
b) optical
c) geometric
d) linkage
e) ionization
Difficulty: Easy
Learning Objective: Use crystal field theory to explain the colour and magnetic properties of complexes.
Section Reference: 19.3 Bonding in Coordination Complexes
16. The complexes Co(NH3)63+ and Mo(CO)6 are isoelectronic and diamagnetic. The first complex is orange and the second complex is white. What can you deduce about the value of ∆ in both of these complexes?
(If needed, use the following equation:
Spectrochemical Series I- < Br- < Cl- < F- < OH‑ < H2O< NH3 < en < NO2- < CN- < CO)
a) ∆ is larger in Mo(CO)6 than in Co(NH3)63+
b) ∆ is 0 in Mo(CO)6
c) ∆ is smaller in Mo(CO)6 than in Co(NH3)63+
d) ∆ is the same in the two complexes
e) ∆ is 0 in Co(NH3)63+
Difficulty: Medium
Learning Objective: Use crystal field theory to explain the colour and magnetic properties of complexes.
Section Reference: 19.3 Bonding in Coordination Complexes
17. What differences might you expect between the two complexes, Fe(CN)64- and FeF64-?
(If needed, use the following equation:
Spectrochemical Series I- < Br- < Cl- < F- < OH‑ < H2O< NH3 < en < NO2- < CN- < CO)
a) Fe(CN)64- will be pale yellow and paramagnetic and FeF64- will be coloured and diamagnetic.
b) Fe(CN)64- will be pale yellow and diamagnetic and FeF64- will be coloured and paramagnetic.
c) Fe(CN)64- will be coloured and paramagnetic and FeF64- will be pale yellow and diamagnetic.
d) Fe(CN)64- will be coloured and diamagnetic and FeF64- will be pale yellow and paramagnetic.
e) Fe(CN)64- will be coloured and paramagnetic and FeF64- will be coloured and paramagnetic.
Difficulty: Medium
Learning Objective: Use crystal field theory to explain the colour and magnetic properties of complexes.
Section Reference: 19.3 Bonding in Coordination Complexes
18. Aqueous copper(I) chloride is nearly colourless whereas aqueous copper(II) chloride is blue in colour. This difference is because
(If needed, use the following equation:
Spectrochemical Series I- < Br- < Cl- < F- < OH‑ < H2O< NH3 < en < NO2- < CN- < CO)
a) the crystal field splitting in copper(I) is much larger than that in copper(II).
b) the crystal field splitting in copper(I) is much smaller than that in copper(II).
c) the electron configuration of copper(II) has all subshells filled.
d) the electron configuration of copper(I) has all subshells filled.
e) copper(I) chloride doesn’t dissolve in water.
Difficulty: Easy
Learning Objective: Use crystal field theory to explain the colour and magnetic properties of complexes.
Section Reference: 19.3 Bonding in Coordination Complexes
19. Which of the following five complexes are paramagnetic with 2 unpaired electrons?
I | II | III | IV | V |
Mn(H2O)62+ | WCl64- | Cr(H2O)62+ | ZrCl64- | Cr(CN)64- |
(If needed, use the following equation:
Spectrochemical Series I- < Br- < Cl- < F- < OH‑ < H2O< NH3 < en < NO2- < CN- < CO)
a) I and II
b) II, IV, and V
c) III
d) IV and V
e) I and III
Difficulty: Medium
Learning Objective: Use crystal field theory to explain the colour and magnetic properties of complexes.
Section Reference: 19.3 Bonding in Coordination Complexes
20. How many chloride ions, Cl-, would you expect to find in a platinum complex described as PtCl4⋅5NH3?
(If needed, use the following equation:
Spectrochemical Series I- < Br- < Cl- < F- < OH‑ < H2O< NH3 < en < NO2- < CN- < CO)
a) 1
b) 2
c) 3
d) 4
e) 0
Difficulty: Medium
Learning Objective: Use crystal field theory to explain the colour and magnetic properties of complexes.
Section Reference: 19.3 Bonding in Coordination Complexes
Feedback: Complex is [Pt(NH3)5Cl]Cl3.
21. Arrange the following complexes in order of increasing orbital splitting enegy: [Co(NH3)6]3+, [Co(NH3)4]2+, [Co(NH3)6]2+.
(If needed, use the following equation:
Spectrochemical Series I- < Br- < Cl- < F- < OH‑ < H2O< NH3 < en < NO2- < CN- < CO)
a) [Co(NH3)6]3+, [Co(NH3)4]2+, [Co(NH3)6]2+
b) [Co(NH3)6]3+, [Co(NH3)6]2+, [Co(NH3)4]2+
c) [Co(NH3)4]2+, [Co(NH3)6]2+,[Co(NH3)6]3+
d) [Co(NH3)6]2+, [Co(NH3)4]2+,[Co(NH3)6]3+
e) [Co(NH3)4]2+, [Co(NH3)6]3+,[Co(NH3)6]2+
Difficulty: Medium
Learning Objective: Use crystal field theory to explain the colour and magnetic properties of complexes.
Section Reference: 19.3 Bonding in Coordination Complexes
Feedback: Orbital splitting energy is larger for octahedral complexes in highest oxidation state.
22. In which of the following complexes would you expect the pairing energy to be larger than the orbital splitting energy?
(If needed, use the following equation:
Spectrochemical Series I- < Br- < Cl- < F- < OH‑ < H2O< NH3 < en < NO2- < CN- < CO)
a) FeCl6-4
b) Fe(CN)6-4
c) Fe(CN)6-3
d) W(CO)6
e) Fe(CO)6
Difficulty: Medium
Learning Objective: Use crystal field theory to explain the colour and magnetic properties of complexes.
Section Reference: 19.3 Bonding in Coordination Complexes
23. The three main functions of metalloproteins are
a) transport and storage agents, catalysts to biochemical reactions, redox agents.
b) transport and storage agents, enzymes and electrons sinks.
c) transport and storage agents, inhibitors to biochemical reactions, electron sinks.
d) inhibitors to biochemical reactions, redox agents and agents to accelerate chemical reactions.
e) inhibitors to chemical reactions, electron sources, oxidizing agents.
Difficulty: Easy
Learning Objective: Explain the importance of transition metal complexes in biological processes.
Section Reference: 19.4 Transition Metals in Biology
24. What is the oxidation state of iron in deoxyhaemoglobin and oxyhaemoglobin?
a) +2, +2
b) +3, +3
c) +2, +3
d) +3, +2
Difficulty: Easy
Learning Objective: Explain the importance of transition metal complexes in biological processes.
Section Reference: 19.4 Transition Metals in Biology
Feedback: In both cases the iron is a d6 ion.
25. Deoxyhaemoglobin is bluish in colour, oxyhaemoglobin is bright red. This indicates that the crystal field splitting is
a) greater in deoxyhaemoglobin since blue light is higher energy than red light.
b) greater in oxyhaemoglobin since red light is higher in energy than blue light.
c) greater in deoxyhaemoglobin since high energy blue light is absorbed.
d) greater in oxyhaemoglobin since high energy blue light is absorbed.
e) greater in deoxyhaemoglobin since low energy red light is absorbed.
Difficulty: Medium
Learning Objective: Explain the importance of transition metal complexes in biological processes.
Section Reference: 19.4 Transition Metals in Biology
Feedback: Students must combine multiple concepts; red colour indicates blue (higher energy) light absorbed and greater crystal field splitting.
26. What are reasons that metals are used in metalloproteins?
a) They help position the reactant molecules to facilitate the reaction.
b) They inhibit electron transfer.
c) They enhance the structural instability of the enzyme.
d) They bind irreversibly to ligands.
e) They contain many thousands of atoms.
Difficulty: Easy
Learning Objective: Explain the importance of transition metal complexes in biological processes.
Section Reference: 19.4 Transition Metals in Biology
27. What is at the active site for superoxide dismutase?
a) Cu+2
b) Zn+2, Cu+2
c) Fe+3 cytochrome
d) FeS cubane
e) Fe hemoglobin
Difficulty: Medium
Learning Objective: Explain the importance of transition metal complexes in biological processes.
Section Reference: 19.4 Transition Metals in Biology
28. Which of the techniques in production of metals takes advantage of different redox properties?
a) roasting
b) leaching
c) refining
d) conversion
e) flotation
Difficulty: Easy
Learning Objective: Explain the chemistry of essential steps in the production of pure metals from ores.
Section Reference: 19.5 Metallurgy
29. Which of the techniques in production of metals takes advantage of different solubilities?
a) roasting
b) leaching
c) flotation
d) conversion
e) smelting
Difficulty: Easy
Learning Objective: Explain the chemistry of essential steps in the production of pure metals from ores.
Section Reference: 19.5 Metallurgy
30. What is the layer above molten iron in a blast furnace called?
a) pig iron
b) water
c) impure oxides
d) slag
e) calcium carbonate
Difficulty: Easy
Learning Objective: Explain the chemistry of essential steps in the production of pure metals from ores.
Section Reference: 19.5 Metallurgy
31. What process must be applied to ilmenite ore (FeTiO3) before it can be converted to titanium metal?
a) reaction with CO
b) reaction with CaO
c) reaction with HCl
d) reaction with Cl2 and C
e) reaction with HNO3
Difficulty: Hard
Learning Objective: Explain the chemistry of essential steps in the production of pure metals from ores.
Section Reference: 19.5 Metallurgy
32. Which of the following groups has primary use as catalysts?
a) group 4 metals (titanium family)
b) group 6 metals
c) the platinum metals
d) the group 11 metals
e) group 12 metals
Difficulty: Easy
Learning Objective: Recognize the importance of transition metals in everyday life.
Section Reference: 19.6 Applications of Transition Metals
33. Which of the metals is most likely to be found in elemental form in nature?
a) group 4 metals (titanium family)
b) group 6 metals
c) the platinum metals
d) the group 11 metals
e) group 12 metals
Difficulty: Easy
Learning Objective: Recognize the importance of transition metals in everyday life.
Section Reference: 19.6 Applications of Transition Metals
34. Which metal is primarily used in the photographic industry?
a) silver
b) copper
c) iron
d) silicon
e) cobalt
Difficulty: Easy
Learning Objective: Recognize the importance of transition metals in everyday life.
Section Reference: 19.6 Applications of Transition Metals
35. The metals of which group are most often used in batteries?
a) group 4 metals (titanium family)
b) group 6 metals
c) platinum
d) group 11 metals
e) group 12 metals
Difficulty: Medium
Learning Objective: Recognize the importance of transition metals in everyday life.
Section Reference: 19.6 Applications of Transition Metals
36. What is the material just one reaction away from chromium metal?
a) Na2CO3
b) FeCrO4
c) Cr2O3
d) Na2Cr2O7
e) Cr3+
Difficulty: Easy
Learning Objective: Recognize the importance of transition metals in everyday life.
Section Reference: 19.6 Applications of Transition Metals
37. Titanium is used in many specialized engineering applications. Which of the following is characteristic of titanium?
a) high strength to weight ratio
b) ease of oxidation
c) high density
d) ease of fabrication
e) availability
Difficulty: Easy
Learning Objective: Recognize the importance of transition metals in everyday life.
Section Reference: 19.6 Applications of Transition Metals
38. Which metals were discovered first?
a) group 4
b) group 6
c) group 9
d) group 10
e) group 11
Difficulty: Easy
Learning Objective: Recognize the importance of transition metals in everyday life.
Section Reference: 19.6 Applications of Transition Metals
ESSAY QUESTIONS
39. What is the oxidation number of Mo in (NH4)2MoS4?
Difficulty: Easy
Learning Objective: Predict periodic properties of transition metals.
Section Reference: 19.1 Overview of the Transition Metals
40. What is the oxidation number of iron in Na2[Fe(CO)4]?
Difficulty: Easy
Learning Objective: Predict periodic properties of transition metals.
Section Reference: 19.1 Overview of the Transition Metals
41. What is the valence electron configuration of the Fe+3 ion?
Difficulty: Easy
Learning Objective: Predict periodic properties of transition metals.
Section Reference: 19.1 Overview of the Transition Metals
42. What is the valence electron configuration of the Mo+2 ion?
Difficulty: Easy
Learning Objective: Predict periodic properties of transition metals.
Section Reference: 19.1 Overview of the Transition Metals
43. What is the valence electron configuration of the Ti atom in the complex TiF64–?
Difficulty: Easy
Learning Objective: Predict periodic properties of transition metals.
Section Reference: 19.1 Overview of the Transition Metals
44. A particular cobalt compound is known to have a coordination number of 6, and found to contain 5 amine groups / Co. In addition, this compound contains chloride, Cl- ions. For every mole of the compound added to an aqueous solution of AgNO3, moles of a white precipitate form. Suggest a structure and explain your reasoning.
Difficulty: Medium
Learning Objective: Recognize and name transition metal coordination complexes.
Section Reference: 19.2 Coordination Complexes
45. Write the missing name or formula for the following:
a) [Co(H2O)5Br]Cl2
b) Magnesium tetrachlorocobaltate(II)
c) K2Ni(CN)4
d) Diamminedichloroplatinum(II)
Difficulty: Medium
Learning Objective: Recognize and name transition metal coordination complexes.
Section Reference: 19.2 Coordination Complexes
46. Write the missing name or formula for the following:
a) K3[Mo(CN)6]
b) [Pt(NH3)4Cl2]SO4
c) (NH4)4[Co(ox)3]
d) [Cr(OH)2(H2O)4]Br
Difficulty: Medium
Learning Objective: Recognize and name transition metal coordination complexes.
Section Reference: 19.2 Coordination Complexes
47. Draw all the isomers for square planar Pt(NH3)2BrCl.
Difficulty: Hard
Learning Objective: Recognize and name transition metal coordination complexes.
Section Reference: 19.2 Coordination Complexes
48. Sketch the geometric isomers for [Co(en)2Cl2]+.
Difficulty: Medium
Learning Objective: Recognize and name transition metal coordination complexes.
Section Reference: 19.2 Coordination Complexes
Feedback: Must show bidentate ligands, and recognize that for octahedral complex there are only two geometric isomers.
49. Which of the following is NOT an isomer of the complex shown below of formula Co(NH3)3Br2Cl+?
I | II | III | IV |
|
|
|
|
Difficulty: Medium
Learning Objective: Recognize and name transition metal coordination complexes.
Section Reference: 19.2 Coordination Complexes
50. Draw and name the two isomers of the metal complex Co(NH3)3Cl3.
Difficulty: Medium
Learning Objective: Recognize and name transition metal coordination complexes.
Section Reference: 19.2 Coordination Complexes
51. Draw and name the two isomers of the metal ion Co(NH3)4Cl2+.
Difficulty: Medium
Learning Objective: Recognize and name transition metal coordination complexes.
Section Reference: 19.2 Coordination Complexes
52. What is the electron configuration according to crystal field splitting of the complex TiF?
Difficulty: Medium
Learning Objective: Use crystal field theory to explain the colour and magnetic properties of complexes.
Section Reference: 19.3 Bonding in Coordination Complexes
53. Write the electron configuration for CoF63- and determine if there are any unpaired electrons and if the complex is paramagnetic or diamagnetic.
Difficulty: Hard
Learning Objective: Use crystal field theory to explain the colour and magnetic properties of complexes.
Section Reference: 19.3 Bonding in Coordination Complexes
54. Which of the following is the crystal field energy diagram for low-spin Co3+?
I | II | III | IV | |
|
|
|
|
Difficulty: Easy
Learning Objective: Use crystal field theory to explain the colour and magnetic properties of complexes.
Section Reference: 19.3 Bonding in Coordination Complexes
55. Draw the crystal field energy diagram for Rh(NH3)63+.
Difficulty: Easy
Learning Objective: Use crystal field theory to explain the colour and magnetic properties of complexes.
Section Reference: 19.3 Bonding in Coordination Complexes
56. Why are 2nd and 3rd row transition metals typically low-spin complexes?
Difficulty: Easy
Learning Objective: Use crystal field theory to explain the colour and magnetic properties of complexes.
Section Reference: 19.3 Bonding in Coordination Complexes
57. The reduction of oxygen accounts for 90% of all the O2 consumed in the biosphere. What is the chemical reaction for reduction of 1 mole of O2?
Difficulty: Easy
Learning Objective: Explain the importance of transition metal complexes in biological processes.
Section Reference: 19.4 Transition Metals in Biology
Feedback: balance reduction of O2
58. Draw crystal field energy diagrams illustrating the difference between the iron atom’s electron configuration in deoxyhemoglobin and oxyhemoglobin.
Difficulty: Medium
Learning Objective: Explain the importance of transition metal complexes in biological processes.
Section Reference: 19.4 Transition Metals in Biology
59. It has been recognized by chemists who specialize in the chemistry of transition metals that the metal’s reactions proceed more slowly as one moves down to the heavier members. If you wanted to slow down the reaction rate to observe the reaction better, which metal(s) might you use to study the chemistry of myoglobin?
Difficulty: Medium
Learning Objective: Explain the importance of transition metal complexes in biological processes.
Section Reference: 19.4 Transition Metals in Biology
60. What is one reason that many metalloproteins have the metal in close proximity to histidine, cysteine, or glutamic acid amino acids?
Difficulty: Hard
Learning Objective: Explain the importance of transition metal complexes in biological processes.
Section Reference: 19.4 Transition Metals in Biology
61. Superoxide dismutase (SOD), an important enzyme found in virtually all aerobic organisms, eliminates damaging O2- via:
Identify the species being reduced and its reduction product and the species being oxidized and its oxidation product.
Difficulty: Medium
Learning Objective: Explain the importance of transition metal complexes in biological processes.
Section Reference: 19.4 Transition Metals in Biology
Feedback: Recognize that this is a disproportionation reaction catalyzed by the SOD enzyme.
62. Chromium is found as the ore, chromite, FeCr2O4. What would be the balanced chemical reaction for the reduction of the ore by coke?
Difficulty: Hard
Learning Objective: Explain the chemistry of essential steps in the production of pure metals from ores.
Section Reference: 19.5 Metallurgy
63. The standard free energies of formation of CO and CO2 as gases are –137.2 kJ/mole and –394.4 kJ/mole respectively. Which substance, coke (C) or CO, is the more powerful reducing agent for producing metals from their oxides if the final product in both cases is CO2?
Difficulty: Medium
Learning Objective: Explain the chemistry of essential steps in the production of pure metals from ores.
Section Reference: 19.5 Metallurgy
64. Given the standard free energies of formation of HCl(g) (–95.3 kJ/mole) and SiCl4(g) (–617.0 kJ/mole), will hydrogen be an effective reagent to reduce SiCl4 to Si near room temperature and explain your answer.
Difficulty: Hard
Learning Objective: Explain the chemistry of essential steps in the production of pure metals from ores.
Section Reference: 19.5 Metallurgy
65. There is considerable concern and debate about controlling CO2 emissions as it is a “greenhouse gas” which can contribute to global warming. If 700 million tons of steel (essentially all iron for these purposes) is produced annually world wide from Fe2O3 using CO as a reducing agent, how much CO2 in kg will be produced as a by-product?
Difficulty: Hard
Learning Objective: Explain the chemistry of essential steps in the production of pure metals from ores.
Section Reference: 19.5 Metallurgy
66. Sphalerite, which has an idealized formula of ZnS, is an important source of zinc. About 6 million tons of zinc are produced annually. If the zinc was produced by roasting of ZnS ore, how many kg of SO2 would be produced?
Difficulty: Hard
Learning Objective: Explain the chemistry of essential steps in the production of pure metals from ores.
Section Reference: 19.5 Metallurgy
67. Although Al2O3 can be dissolved in an acidic aqueous solution, reduction of Al2O3 to form Al metal is performed at very high temperature in a molten salt solution; Cr(s) is formed by electrolysis of a solution containing dissolved Cr2O3 in sulphuric acid. Why is chromium metal produced from an aqueous solution and aluminium metal from a molten salt?
Difficulty: Medium
Learning Objective: Recognize the importance of transition metals in everyday life.
Section Reference: 19.6 Applications of Transition Metals
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