Deck 22: Coordination Chemistry

Question 1

What is the electron configuration of a ground-state Fe²⁺ ion?

A) [Ar]3d⁵
B) [Ar]4s¹3d⁵
C) [Ar]3d⁶
D) [Ar] 4s¹4d⁵
E) [Ar]4d⁶

Answer 1

[Ar]4s¹3d⁵

Question 2

What is the electron configuration of a ground-state Ag atom?

A) [Kr]5s¹4d¹⁰
B) [Kr]5s¹5d¹⁰
C) [Kr]5s²4d⁹
D) [Kr]5s²5d⁹
E) [Kr]5d¹⁰

Answer 2

[Kr]5s¹4d¹⁰

Question 3

How many 4d electrons does a ground-state Ag⁺ ion have?

A) 8
B) 1
C) 10
D) 2
E) 9

Answer 3

10

Question 4

How many 3d electrons does a ground-state Sc³⁺ ion have?

A) 1
B) 3
C) 2
D) 10
E) 0

Question 5

How many 3d electrons does a ground-state Pd²⁺ ion have?

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

Question 6

What is the electron configuration of a ground-state Cu⁺ ion?

A) [Ar]3d¹⁰
B) [Ar]4d¹⁰
C) [Ar]3d⁹
D) [Ar]4d⁹
E) None of these choices.

Question 7

Which statement is correct about coordination compounds?

A) They consist only of nonmetals.
B) They contain ionic bonds.
C) They are formed by reactions of metal ions with groups of anions or polar molecules.
D) They contain only metals.

Question 8

What type of structure is exhibited by most of the transition metals?

A) Close-packed
B) Tetrahedral
C) Trigonal planar
D) Trigonal pyramidal
E) None of the answers is correct.

Question 9

What is the electron configuration of a ground-state Zn²⁺ ion?

A) 1s²2s²2p⁶3s²3p⁶4s¹3d⁹
B) 1s²2s²2p⁶3s²3p⁶4s¹4d⁹
C) 1s²2s²2p⁶3s²3p⁶4s²3d⁸
D) 1s²2s²2p⁶3s²3p⁶4s²4d⁸
E) 1s²2s²2p⁶3s²3p⁶3d¹⁰

Question 10

How many 4d electrons does a ground-state Cd²⁺ ion have?

A) 8
B) 2
C) 9
D) 7
E) 10

Question 11

How many 3d electrons does a ground-state Nb³⁺ ion have?

A) 2
B) 4
C) 3
D) 10
E) 5

Question 12

What is the electron configuration of a ground-state Cr atom?

A) 1s²2s²2p⁶3s²3p⁶4s²3d⁴
B) 1s²2s²2p⁶3s²3p⁶3d⁶
C) 1s²2s²2p⁶3s²3p⁶4s¹4d⁵
D) 1s²2s²2p⁶3s²3p⁶4s²4d⁴
E) 1s²2s²2p⁶3s²3p⁶4s¹3d⁵

Question 13

Which are the most common transition metals?

A) The transition metals in the 3^rd period.
B) The transition metals in the 4^th period.
C) The elements in Group 6B.
D) The transition metals in the 5^th period.
E) The transition metals in the 6^th period.

Question 14

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

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

Question 15

Which statement is correct about transition metals?

A) They have incompletely filled d subshells.
B) They form ions with incompletely filled d subshells.
C) They form paramagnetic compounds.
D) They have catalytic activity.
E) All of the answers are correct.

Question 16

What is the electron configuration of a ground-state Cu atom?

A) 1s²2s²2p⁶3s²3p⁶4s¹3d¹⁰
B) 1s²2s²2p⁶3s²3p⁶3d¹⁰
C) 1s²2s²2p⁶3s²3p⁶4s¹4d¹⁰
D) 1s²2s²2p⁶3s²3p⁶4s²4d⁹
E) 1s²2s²2p⁶3s²3p⁶4s²3d⁹

Question 17

What is the electron configuration of a ground-state Nb²⁺ ion?

A) 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹
B) 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶4d³
C) 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s¹4d²
D) 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶4d⁵
E) 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d³

Question 18

How many 3d electrons does a ground-state Fe³⁺ ion have?

A) 3
B) 5
C) 6
D) 7
E) 9

Question 19

How many 4d electrons does a ground-state Mo atom have?

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

Question 20

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 21

Write the formula for diamminedichloroethylenediaminecobalt(III) bromide.

A) [CoCl₂(en)(NH₃)₂]Br
B) [CoCl₂(en)(NH₃) ₂]Br₂
C) [CoCl₂(en)₂(NH₃)₂]Br
D) [CoCl₂(en)₂(NH₃)₂]Br₂
E) (NH₃)₂Cl₂(en)Co₃Br

Question 22

Which of the following ligands has two different types of donor atoms?

A) NH₃
B) H₂O
C) NH₄⁺
D) NO₂^-
E) ethylenediamine

Question 23

What is the formula for pentaamminechlorocobalt(III) chloride?

A) [Co(NH₃)₅Cl]Cl
B) [Co(NH₃)₅Cl]Cl₂
C) [Co(NH₃)₅Cl]Cl₃
D) [Co(NH₃)₅Cl]Cl₄
E) [CoCl₃](NH₃)₅

Question 24

In the compound K[Co(C₂O₄)₂(H₂O)₂] (where C₂O₄^2- = oxalate) the oxidation number and coordination number of cobalt are ________ and ________, respectively.

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

Question 25

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

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

Question 26

What is the systematic name for [Cu(NH₃)₄]Cl₂?

A) dichlorotetraamminecuprate(II)
B) tetraamminecopper(II) chloride
C) copper(II) ammonium chloride
D) tetraaminocopper(II) chloride
E) tetramminecopper(II) dichloride

Question 27

What is the systematic name for [CoCl₃(H₂O)]^-?

A) cobalt(III) chloride monohydrate
B) aquatrichlorocobalt(II)
C) aquatrichlorocobaltate(II)
D) aquatrichlorocobaltite(I)
E) monoaquotris(chloro)cobalt(IV)

Question 28

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

A) 2; 0
B) 4; +4
C) 5; 0
D) 4; +2
E) 6; +2

Question 29

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 30

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

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 31

The compound K₃[Fe(CN)₆] is used in calico printing and wool dyeing. What is its systematic name?

A) potassium iron(III) hexacyanate
B) tripotassium iron(III) hexacyanate
C) potassium hexacyanoferrate(III)
D) potassium hexacyanideferrate
E) tripotassium hexacyanoiron(III)

Question 32

What is the systematic name for Cr(CO)₃(NH₃)₃?

A) chromiumtriaminotricarbonyl
B) triamminechromium carbonate
C) triamminetricarbonylchromate(0)
D) triamminetricarbonylchromium(0)
E) tris(amino)tris(carbonyl)chromium

Question 33

Which of the following geometries is not common in transition-metal complex ions?

A) Tetrahedral
B) Octahedral
C) Linear
D) Trigonal planar
E) Square planar

Question 34

What is the coordination number of cobalt in the complex ion [Co(en)Cl₄]^-? (en = ethylenediamine)

A) 1
B) 2
C) 4
D) 6
E) 8

Question 35

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 36

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

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

Question 37

Which of the following metals is capable of forming complexes spanning the smallest range of oxidation numbers?

A) Cu
B) Sc
C) Fe
D) Mn
E) Ni

Question 38

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

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

Question 39

In the coordination compound [Cr(NH₃)₂(en)Cl₂]Br₂, the coordination number (C.N.) and oxidation number (O.N.) of the metal atom, respectively, are

A) C.N. = 6; O.N. = +4.
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 40

Which of the following metals is capable of forming complexes spanning the largest range of oxidation numbers?

A) Cu
B) Sc
C) Fe
D) Mn
E) Ni

Question 41

Consider the following octahedral complex structures, each involving ethylene diamine and two different, unidentate ligands X and Y. Which, if any, of the following pairs are optical isomers?

A) Structures 1 and 2
B) Structures 1 and 3
C) Structures 1 and 4
D) Structures 3 and 4
E) Structures 1, 2, 3, and 4

Question 42

Consider the following structures (1 and 2 are octahedral; 3 and 4 are square planar). Which one of the following statements about the above structures is correct?

A) Structures 1 and 2 are superimposable.
B) Structures 1 and 2 are geometric isomers.
C) Structures 3 and 4 are structural isomers.
D) Structures 3 and 4 are optical isomers.
E) Structures 3 and 4 are geometric isomers.

Question 43

Which of these diagrams represent the crystal field splitting between d orbitals in a tetrahedral complex?

A)
B)
C)
D)

Question 44

In the spectrochemical series, which one of the following ligands has the strongest field?

A) H₂O
B) CN^-
C) NH₃
D) OH^-
E) Cl^-

Question 45

Which of the following octahedral complexes should have the largest crystal field splitting energy, Δ?

A) [Cr(H₂O)₆]³⁺
B) [Cr(SCN)₆]³
C) [Cr(NH₃)₆]³⁺
D) [Cr(CN)₆]^3-
E) [Cr(en)₃]³⁺ (en = ethylenediamine)

Question 46

Which of the following ions is most likely to form colored compounds?

A) Sc³⁺
B) Cu⁺
C) Zn²⁺
D) Cr³⁺
E) Ca²⁺

Question 47

The crystal field splitting energy, Δ,

A) is larger for tetrahedral complexes than for octahedral complexes.
B) depends on the metal but not on the ligand.
C) determines the color of a complex.
D) is larger for ionic ligands like chloride than for molecular ligands like carbon monoxide, CO.
E) determines the charge of a complex.

Question 48

What is the systematic name for [Ru(NH₃)₂(en)](NO₃)₂?

A) (ethylenediamine)diammineruthenium(II) nitrate
B) diamminebis(ethylenediamine)ruthenium(III) nitrate
C) diammine(ethylenediamine)ruthenium(II) nitrate
D) diammine(ethylenediamine)nitratoruthenium(III)
E) bis(ethylene)diamminenitratoruthenate(II)

Question 49

Which of these diagrams represent the crystal field splitting between d orbitals in an octahedral complex?

A)
B)
C)
D)

Question 50

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

A)
B)
C)
D)

Question 51

Which of the following ions is least likely to form colored compounds?

A) Mn²⁺
B) Cr⁵⁺
C) Sc³⁺
D) Fe³⁺
E) Co²⁺

Question 52

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 53

Which of the following ligands is most likely to form a low-spin octahedral complex with iron(III)?

A) Cl^-
B) H₂O
C) NH₃
D) OH^-
E) CO

Question 54

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 55

Which of the following species could exist as isomers?

A) [Co(H₂O)₄Cl₂]⁺
B) [Pt(NH₃)Br₃]^-
C) [Pt(en)Cl₂]
D) [Pt(NH₃)₃Cl]⁺
E) [CuBr₄]²⁺

Question 56

Write the formula for sodium tetracyanonickelate(II).

A) Na[Ni(CN)₄]
B) Na[Ni(CN)₄]₂
C) Na₂[Ni(CN)₄]
D) Na₄[Ni(CN)₄]
E) Na[(NiCN)₄]

Question 57

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 (Δ) 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 58

Consider the following octahedral complex structures, each involving ethylene diamine and two different, unidentate ligands X and Y. Which one of the following statements about these structures is incorrect?

A) Structures 1 and 2 are optical isomers.
B) Structures 1 and 3 are optical isomers.
C) Structures 1 and 3 are different complexes.
D) Structures 1 and 4 are geometrical isomers.
E) Structures 3 and 4 are the same complex.

Question 59

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 choices are correct.
E) None of these choices.

Question 60

In a coordination compound involving a complex ion of square planar geometry, which of the following types of isomerism is/are never possible?

A) Geometric
B) Optical
C) Linkage
D) Coordination
E) More than one of these choices is correct.

Question 61

Which one of these species is a bidentate ligand?

A) CN^-
B) NH₃
C) CO
D) H₂NCH₂CH₂NH₂
E) EDTA

Question 62

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

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

Question 63

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 64

The net rotation of plane-polarized light by a racemic mixture is ________.

A) to the right
B) to the left
C) zero

Question 65

What is the name of the atom in a ligand that is bound directly to the metal atom?

A) Acceptor atom
B) Donor atom
C) Chelating atom
D) Coordinator
E) Chelating agent

Question 66

Which of the following ions could exist in either the high-spin or low-spin state in an octahedral complex?

A) Sc³⁺
B) Ni²⁺
C) Mn²⁺
D) Ti⁴⁺
E) Zn²⁺

Question 67

A bidentate ligand always

A) forms bonds to two metal ions.
B) has a charge of 2+ or 2-.
C) forms complex ions with a charge of 2+ or 2-.
D) has two donor atoms.
E) has medical uses.

Question 68

Which of the following ions could exist in only the high-spin state in an octahedral complex?

A) Cr²⁺
B) Mn⁴⁺
C) Fe³⁺
D) Co³⁺
E) Ni²⁺

Question 69

Cisplatin 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 70

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 71

The complex ion [Cr(CN)₆]^4- has magnetic properties that correspond to how many unpaired electrons?

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

Question 72

How many unpaired electrons will there be in a high-spin octahedral complex of Fe(II)?

A) 0
B) 2
C) 4
D) 6
E) 8

Question 73

Which of the following will be paramagnetic?

A) V⁵⁺
B) Ni²⁺
C) Mn⁷⁺
D) Ti⁴⁺
E) Zn²⁺

Question 74

What is the name of the molecules or ions that surround the metal in a complex ion?

A) Chelaters
B) Donors
C) Acceptors
D) Coordinators
E) Ligands

Question 75

Iron(III) forms an octahedral complex with the ligand CN^-. How many unpaired electrons are in the d orbitals of iron?

A) 1
B) 3
C) 5
D) 7
E) 9

Question 76

Which of the following will be diamagnetic?

A) Ni²⁺
B) Cr²⁺
C) Mn²⁺
D) Co³⁺
E) Ti⁴⁺

Question 77

How many geometric isomers can the following square-planar complex have?

A) 1
B) 2
C) 3
D) 4
E) 6

Question 78

Which of the following ligands is most likely to form a high-spin octahedral complex with cobalt(II)?

A) CN^-
B) en (ethylenediamine)
C) NH₃
D) CO
E) I^-

Question 79

If a solution absorbs green light, what is its likely color?

A) Red
B) Violet
C) Orange
D) Yellow
E) Blue

Question 80

Which one of these species is a monodentate ligand?

A) CN^-
B) EDTA
C) C₂O₄^-
D) H₂NCH₂CH₂NH₂