Deck 22: Transition Metal Chemistry and Coordination Compounds

Question 1

Give the coordination number (C.N.)and oxidation number (O.N.)of the metal atom in the coordination compound [Cr(NH₃)₂(en)Cl₂].

A)C.N.= 4; O.N.= +2.
B)C.N.= 5; O.N.= +3.
C)C.N.= 5; O.N.= +2.
D)C.N.= 6; O.N.= +3.
E)C.N.= 6; O.N.= +2.

Answer 1

C.N.= 6; O.N.= +2.

Question 2

The electron configuration of a Cr³⁺ ion is

A)[Ar]3d⁵.
B)[Ar]4s¹3d².
C)[Ar]3d³.
D)[Ar]4s¹3d⁵.
E)[Ar]4s²3d⁴.

Answer 2

[Ar]3d³.

Question 3

The total number of electrons in the 3d orbitals of Ti³⁺ is

A)0
B)1
C)2
D)3
E)4

Answer 3

1

Question 4

Which response gives the correct coordination number (C.N.)and oxidation number (O.N.)of the transition metal atom in [Co(NH₃)₂(H₂O)₂Cl₂]⁺?

A)C.N.= 2; O.N.= +3
B)C.N.= 3; O.N.= +1
C)C.N.= 4; O.N.= +2
D)C.N.= 6; O.N.= +1
E)C.N.= 6; O.N.= +3

Question 5

The total number of electrons in the 3d orbitals of Cr³⁺ is

A)1
B)2
C)3
D)4
E)5

Question 6

Assuming a coordination complex is formed with Fe²⁺ and 1,10-phenanthroline (shown below), which of the following statements is true?

A)If two 1,10-phenanthroline molecules are coordinated to the iron ion, then the coordination number is 2.
B)If two 1,10-phenanthroline molecules are coordinated to the iron ion, then the coordination number is 6.
C)If three 1,10-phenanthroline molecules are coordinated to the iron ion, then the coordination number is 3.
D)If three 1,10-phenanthroline molecules are coordinated to the iron ion, then the coordination number is 6.
E)If four 1,10-phenanthroline molecules are coordinated to the iron ion, then the coordination number is 4.

Question 7

In the complex ion [Fe(CN)₆]^4-, the oxidation number of Fe is

A)+1.
B)+2.
C)+3.
D)-4.
E)+6.

Question 8

The electron configuration of a nickel atom is

A)[Ar]4s²3d⁶.
B)[Ar]4s¹3d⁷.
C)[Ar]3d⁸.
D)[Ar]4s²3d⁸.
E)[Ar]3d¹⁰.

Question 9

The total number of electrons in the 3d orbitals of a titanium atom is

A)1
B)2
C)3
D)4
E)5

Question 10

In the complex ion [Co(en)₂Br₂]⁺, the oxidation number of Co is

A)+1.
B)+2.
C)+3.
D)-2.
E)-1.

Question 11

How would you expect the molecule 1,10-phenanthroline (shown below)to function as a ligand?

A)It would be expected to be a monodentate ligand.
B)It would be expected to be a bidentate ligand.
C)It would be expected to be a tridentate ligand.
D)It would be expected to be a tetradentate ligand.
E)It would not be expected to function as a ligand.

Question 12

How many 3d electrons does a Mn²⁺ ion have?

A)1
B)2
C)3
D)4
E)5

Question 13

The electron configuration of a Ti atom is

A)[Ne]3s²3d².
B)[Ne] 3s²4d².
C)[Ar]4s²3d².
D)[Ar]4s²4d².
E)[Ar]3d⁴.

Question 14

The total number of electrons in the 3d orbitals of Co³⁺ is

A)4
B)5
C)6
D)7
E)10

Question 15

How many 3d electrons does a V³⁺ ion have?

A)6
B)5
C)4
D)3
E)2

Question 16

In K₄[Fe(CN)₆], how many 3d electrons does the iron atom have?

A)3
B)4
C)5
D)6
E)7

Question 17

In the complex ion [Cr(C₂O₄)₂(H₂O)₂]^-, the oxidation number of Cr is

A)+1.
B)+2.
C)+3.
D)-2.
E)-1.

Question 18

The electron configuration of an Fe²⁺ ion is

A)[Ar]4s²4d⁴.
B)[Ar]4s²3d⁶.
C)[Ar]3d³.
D)[Ar]3d⁵.
E)[Ar]3d⁶.

Question 19

The total number of electrons in the 3d orbitals of a copper atom is

A)6
B)7
C)8
D)9
E)10

Question 20

The electron configuration of a Co³⁺ ion is

A)[Ar]3d⁶.
B)[Ar]4s¹3d⁵.
C)[Ar] 4s²3d⁴.
D)[Ar]3d⁵.
E)[Ar]3d⁴.

Question 21

Which of these square planar complex ions can have cis-trans isomers?

A)[Pt(NH₃)₄]²⁺
B)[Ni(NH₃)₄]²⁺
C)[Pt(NH₃)₂Cl₂]
D)[Pt(NH₃)Cl₃]^-
E)[Ni(NH₃)₃Cl]⁺

Question 22

The numbers of geometrical isomers and optical isomers of the complex ion [Co(en)₃]³⁺ are, respectively,

A)2 and 2.
B)1 and 1.
C)3 and 2.
D)1 and 2.
E)2 and 4.

Question 23

The best name for K₄[FeCl₂(CN)₄] is

A)tetrapotassium dichlorodicyanoiron(II).
B)potassium dichlorodicyanoiron(II).
C)potassium dichlorodicyanoferrate(III).
D)tetrapotassium dichlorobis(cyano)iron(III).
E)potassium dichlorotetracyanoferrate(II).

Question 24

In the complex ion [ML₆]ⁿ⁺, Mⁿ⁺ has five d electrons and L is a strong field ligand.According to crystal field theory, the magnetic properties of the complex ion correspond to how many unpaired electrons?

A)0
B)1
C)2
D)3
E)5

Question 25

The correct formula for the dichlorobis(ethylenediamine)chromium(III)ion is

A)[Cr(en)₂Cl₂]³⁺.
B)[Cr(en)Cl₂]⁺.
C)[Cr(en)₂Cl₂]²⁺.
D)[Cr(en)₂Cl₂]⁺.
E)[Cr(en)₃Cl₂]⁺.

Question 26

In the coordination compound [Cr(NH₃)(en)₂Cl]Br₂, the coordination number (C.N.)and oxidation number (O.N.)of the metal atom are, respectively,

A)C.N.= 6; O.N.= +4.
B)C.N.= 6; O.N.= +3.
C)C.N.= 5; O.N.= +2.
D)C.N.= 4; O.N.= +2.
E)C.N.= 4; O.N.= +3.

Question 27

In the coordination compound K₂[Co(en)Cl₄], the coordination number (C.N.)and oxidation number (O.N.)of cobalt are

A)C.N.= 6; O.N.= +2.
B)C.N.= 6; O.N.= +3.
C)C.N.= 5; O.N.= +2.
D)C.N.= 5; O.N.= +4.
E)C.N.= 4; O.N.= +3.

Question 28

Which of these complex ions would absorb light with the longest wavelength?

A)[Co(H₂O)₆]²⁺
B)[Co(NH₃)₆]²⁺
C)[CoF₆]^4-
D)[Co(CN)₆]^4-
E)[Co(en)₆]²⁺

Question 29

Cis-trans isomerism is exhibited by which one of these ions?

A)[Pd(NH₃)₃Cl]⁺
B)[Co(NH₃)₅Cl]²⁺
C)[Fe(CN)₆]^3-
D)All of the above.
E)None of the above.

Question 30

In the complex ion [ML₆]ⁿ⁺, Mⁿ⁺ has seven d electrons and L is a strong field ligand.According to crystal field theory, the magnetic properties of the complex ion correspond to how many unpaired electrons?

A)0
B)1
C)2
D)3
E)5

Question 31

In the complex ion [ML₆]ⁿ⁺, Mⁿ⁺ has six d electrons and L is a weak field ligand.According to crystal field theory, the magnetic properties of the complex ion correspond to how many unpaired electrons?

A)0
B)1
C)2
D)3
E)4

Question 32

A complex with the composition [MA₂B₂]X₂ is found to have no geometrical isomers. Both A and B are monodentate ligands. The structure of the complex is

A)linear.
B)square planar.
C)tetrahedral.
D)octahedral.

Question 33

Which of these ligands produces the weakest crystal field?

A)CN^-
B)I^-
C)OH^-
D)H₂O
E)NH₃

Question 34

Which of these ligands produces the strongest crystal field?

A)Cl^-
B)CO
C)OH^-
D)H₂O
E)NH₃

Question 35

In the coordination compound [Co(en)₂Cl₂]Cl, the coordination number and oxidation number of the central atom are, respectively,

A)4, +3.
B)6, +2.
C)4, +2.
D)6, +3.
E)4, +1.

Question 36

The coordination compound shown below has

A)two monodentate ligands and two bidentate ligands.
B)three monodentate ligands and two bidentate ligands.
C)four monodentate ligands and two bidentate ligands.
D)one monodentate ligand and four bidentate ligands.
E)four bidentate ligands.

Question 37

In the complex ion [ML₆]ⁿ⁺, Mⁿ⁺ has seven d electrons and L is a weak field ligand.According to crystal field theory, the magnetic properties of the complex ion correspond to how many unpaired electrons?

A)0
B)1
C)2
D)3
E)5

Question 38

In the coordination compound [Pt(NH₃)₂Cl₂], the coordination number and oxidation number of the central atom are, respectively,

A)2, 0.
B)4, 4.
C)5, 0.
D)4, 2.
E)6, 2.

Question 39

The best name for the complex shown below is

A)cobalt(III)bis(ethylenediamine)bromide.
B)dibromobis(ethylenediamine)cobalt(III)bromide.
C)dibromidedi(ethylenediamine)cobalt(III)bromide.
D)dibromodiethylenediaaminecobalt(III)bromide.
E)tribromobis(ethylenediamine)cobalt(III).

Question 40

Which of these electron energy level patterns would absorb light with the shortest wavelength?

Question 41

A molecule or ion that provides an electron pair for coordinate covalent bond formation is called a Lewis ________.

Question 42

Copper can be separated from iron in the ore chalcopyrite (CuFeS₂)by heating the ore in the presence of oxygen to form copper(I)sulfide, iron(II)oxide, and sulfur dioxide.Write a balanced chemical equation for this process.

Question 43

Two complex ions containing Ni are [Ni(NH₃)₆]²⁺, which is blue, and [Ni(en)₃]²⁺, which is purple. Which one of these statements is true?

A)The crystal field splitting energy ( $\Delta$ )is greater for [Ni(NH₃)₆]²⁺ than for [Ni(en)₃]²⁺.
B)[Ni(en)₃]²⁺ absorbs light in the violet region of the spectrum.
C)Both complex ions are diamagnetic.
D)The energy of the photon absorbed by [Ni(en)₃]²⁺ is greater than that absorbed by [Ni(NH₃)₆]²⁺.
E)The wavelength of the light absorbed by [Ni(en)₃]²⁺ is greater than the wavelength absorbed by [Ni(NH₃)₆]²⁺.

Question 44

What is the oxidation number of cobalt in [Co(NH₃)₆]Cl₃?

Question 45

What terms describe the geometric isomers that are possible for the complex [CrF₂Cl₄]^3-?

Question 46

How many unpaired electrons are there in the complex ion [Mn(CN)₆]^3-?

A)0
B)1
C)2
D)3
E)4

Question 47

Cis-platinum complexes are

A)used in the extraction of silver and gold.
B)effective antidotes for heavy metal poisoning (e.g., Pb²⁺ and Hg²⁺).
C)used to provide nutrients for plants.
D)used to prevent eutrophication of lakes.
E)effective antitumor agents.

Question 48

What is the coordination number of chromium in Cr(en)₂Cl₂?

Question 49

Consider the [CoCl₆]^4- ion. Which response includes all the following statements that are true and no false statements? I.The oxidation number of Co is -4.
II. The coordination number of cobalt is 6.
III.It is paramagnetic.
IV.It is a low-spin complex.

A)I, II, III, IV
B)I, IV
C)II, III
D)I, III
E)III, IV

Question 50

What is the coordination number of cobalt in [Co(NH₃)₆]Cl₃?

Question 51

Two well-known complex ions containing Ni are [Ni(H₂O)₆]²⁺, which is green, and [Ni(en)₃]²⁺, which is purple. Which one of these statements is true?

A)The crystal field splitting energy ( $\Delta$ )is greater for [Ni(en)₃]²⁺ than for [Ni(H₂O)₆]²⁺.
B)[Ni(en)₃]²⁺ absorbs energy in the red region of the spectrum.
C)Both complex ions are diamagnetic.
D)[Ni(H₂O)₆]²⁺ transmits light with wavelengths of approximately 650-700 nm.
E)The green complex absorbs green light.

Question 52

How many unpaired electrons does the manganese ion have in [Mn(CN)₆]^4-?

A)1 unpaired electron
B)2 unpaired electrons
C)3 unpaired electrons
D)5 unpaired electrons
E)No unpaired electrons

Question 53

What is the oxidation number of Fe in [Fe(CN)₆]^4-?

Question 54

A molecule or atom that accepts an electron pair to form a coordinate covalent bond is called a Lewis _______.

Question 55

How many geometric isomers are possible for the complex [CrF₃Br₃]^3-? Draw these isomers.

Question 56

Draw and label the geometric isomers of [CrF₂Cl₄]^3-?

Question 57

Labile complexes are coordination complexes that

A)are labeled with a radioactive isotope.
B)are thermodynamically stable.
C)are thermodynamically unstable.
D)undergo rapid ligand exchange reactions.
E)undergo very slow ligand exchange reactions.

Question 58

Ethylenediaminetetraacetic acid (EDTA)is

A)not useful as a chelating agent.
B)an effective antidote for heavy metal poisoning (e.g., Pb²⁺ and Hg²⁺).
C)a monodentate ligand.
D)known to form unstable complex ions with Fe³⁺, Hg²⁺, and Zn²⁺.
E)known to form complexes with platinum that inhibit the growth of cancerous cells.

Question 59

What is the coodination number of silver in [Ag(NH₃)₂]Cl?

Question 60

The ion [Co(NH₃)₆]²⁺ is octahedral and high spin. This complex is

A)paramagnetic, with 1 unpaired electron.
B)paramagnetic, with 3 unpaired electrons.
C)paramagnetic, with 4 unpaired electrons.
D)paramagnetic, with 5 unpaired electrons.
E)diamagnetic.

Question 61

Write the chemical formula of diamminedichloroplatinum(II).

Question 62

Predict the number of unpaired electrons in the [Fe(CN)₆]^4- ion.

Question 63

Predict the number of unpaired electrons in the [Cr(en)₃]²⁺ ion.

Question 64

Name the complex ion [Cr(en)₂(H₂O)₂]²⁺.

Question 65

The systematic name of the coordination compound K₂[Co(H₂O)₂I₄] is potassium diaquotetraiodocobaltate(II).

Question 66

Write the chemical formula of triammineaquodichlorochromium(III)chloride.

Question 67

Predict the number of unpaired electrons in the [CrCl₆]^4- ion.

Question 68

Name the complex ion [CuCl₃Br(NH₃)₂]^2-.

Question 69

Write the chemical formula of the dibromobis(oxalato)cobaltate(III)ion.

Question 70

The neutral monodentate ligand L forms the complex ion [CrL₆]²⁺, and the magnetic properties of this complex correspond to 2 unpaired electrons.Is L a strong-field or weak-field ligand? Explain your reasoning.

Question 71

Bidentate and polydentate ligands are also called chelating agents.

Question 72

The oxidation number of Co in [Co(NH₃)₄Cl₂]Cl is +1.

Question 73

Predict the number of unpaired electrons in the [Fe(CN)₆]^3- ion.

Question 74

In the following pair of complex ions, choose the one that absorbs light at a shorter wavelength.

A)[Co(NH)₆]³⁺
B)[CoCl₆]^3-

Question 75

In the following pair of complex ions, choose the one that absorbs light at a longer wavelength.

A)[Co(H₂O)₆]²⁺
B)[Co(NH₃)₆]²⁺

Question 76

Name the complex ion [Co(H₂O)₄Cl₂]⁺.

Question 77

In transition metal complexes, the metal ions are Lewis acids.

Question 78

The correct formula for the dibromobis(oxalato)cobaltate(III)ion is [Co(C₂O₄)Br₂]³⁺.

Question 79

Give (a)the oxidation number of the metal, (b)the number of d electrons, (c)the coordination number, (d)the charge of the complex ion, and (e)the number and type of ligands for the coordination compound shown below.

Question 80

Name the complex ion [Ni(CN)₄]^2-.