Deck 16: Coordination Compounds-The Colorful Chemistry of Metals

Question 1

Which of the following species is a Lewis base?

A)H⁺
B)Cs⁺
C)NF₃
D)NF₄⁺
E)NH₄⁺

Answer 1

NF₃

Question 2

A Lewis base is __________

A)an electron-pair acceptor.
B)an electron-pair donor.
C)a proton donor.
D)a proton acceptor.
E)never viewed also as a Brønsted-Lowry base.

Answer 2

an electron-pair donor.

Question 3

Prussian blue has an idealized chemical formula of Fe₄[Fe(CN)₆]₃.What is the charge on the counter ions? (Note: the charge on the iron ion in the complex ion is an integer.)

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

Answer 3

+3

Question 4

What is the oxidation state of cobalt in the [Co(NH₃)₄Cl₂]⁺ complex ion?

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

Question 5

What is the oxidation state of the metal atom in the complex ion in K[Pt(NH₃)Cl₅]?

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

Question 6

Identify the Lewis base in the following reaction: SO₂(g)+ H₂O( ) $\to$ H₂SO₃(aq)

A)SO₂
B)H₂O
C)H₂SO₃
D)None of these is a base.
E)All of these are bases.

Question 7

In the following reaction,which species is the Lewis base? Cu²⁺(aq)+ NH₃(aq) $\leftrightarrows$ Cu(NH₃)²⁺(aq)

A)Cu²⁺
B)NH₃
C)[Cu(NH₃)]²⁺
D)None of these is a base.
E)All of these are bases.

Question 8

Identify the Lewis acid in the following reaction: PH₃(aq)+ H⁺(aq) $\to$ PH₄⁺(aq)

A)PH₄⁺
B)H⁺
C)PH₃
D)None of these is an acid.
E)All of these are acids.

Question 9

When NF₃ reacts with BF₃ to form F₃NBF₃,__________

A)a complex ion is formed.
B)an ionic bond is formed.
C)the bond is formed by sharing an electron from NF₃ and an electron from BF₃.
D)a coordinate covalent bond is formed.
E)a covalent bond is formed.

Question 10

A ligand is any __________ forming a coordinate bond to a metal cation.

A)Lewis acid
B)ion
C)Lewis base
D)organic compound
E)species

Question 11

A Lewis acid is __________

A)a proton donor.
B)a proton acceptor.
C)an electron-pair donor.
D)an electron-pair acceptor.
E)is never viewed also as a Brønsted-Lowry acid.

Question 12

A Lewis acid is any species capable of __________ an electron pair.

A)accepting
B)donating
C)creating
D)neutralizing
E)losing

Question 13

Identify the Lewis base in the following reaction: PH₃(aq)+ H⁺(aq) $\to$ PH₄⁺(aq)

A)PH₄⁺
B)H⁺
C)PH₃
D)None of these is a base.
E)All of these are bases.

Question 14

Identify the Lewis acid in the following reaction: NH₃(aq)+ H₂O( ) $\to$ NH₄⁺(aq)+ OH^-(aq)

A)NH₃
B)H₂O
C)NH₄⁺
D)OH^-
E)None of these is a base.

Question 15

Prussian blue has an idealized chemical formula of Fe₄[Fe(CN)₆]₃.What is the charge on the iron atom in the complex ion? (Note: the charge on the iron counter ions is an integer.)

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

Question 16

A Lewis base is any species capable of __________ an electron pair.

A)accepting
B)donating
C)creating
D)neutralizing
E)gaining

Question 17

A coordinate covalent bond forms when a chemical species __________

A)donates one electron to another species to form a covalent bond.
B)accepts a pair of electrons and becomes an anion.
C)accepts one electron from another species to form a covalent bond.
D)accepts an electron and becomes an anion.
E)donates a pair of electrons to another species to form a covalent bond.

Question 18

Which of the following statements regarding complex ions and coordination compounds is NOT correct?

A)Ligands function as electron pair donors.
B)A metal cation acts as a Lewis acid in a complex ion.
C)Ligands occupy the inner coordination sphere of the cation.
D)The coordination number refers to the number of electron pairs surrounding a metal ion in a complex.
E)Counter ions form coordinate covalent bonds with the ligands in a complex.

Question 19

In the following reaction,which species is the Lewis acid? Cu²⁺(aq)+ NH₃(aq) $\leftrightarrows$ Cu(NH₃)²⁺(aq)

A)Cu²⁺
B)NH₃
C)[Cu(NH₃)]²⁺
D)None of these is an acid.
E)All of these are acids.

Question 20

What is the oxidation state of nickel in tetracarbonylnickel,Ni(CO)₄?

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

Question 21

The correct name for the complex ion [Co(NH₃)₅Cl]²⁺ is __________

A)pentamminechlorocobaltate(III).
B)pentamminechlorocobalt(II).
C)chloropentamminecobalt(III).
D)pentamminechlorocobalt(III).
E)pentamminechlorocobalt.

Question 22

What is the coordination number around the Co ion in [Co(NH₃)₆][CrF₆]?

A)2
B)1
C)6
D)5
E)7

Question 23

What is the coordination number around the Cr ion in [Co(NH₃)₆][CrF₆]?

A)2
B)1
C)6
D)5
E)7

Question 24

What is the coordination number of cobalt in the [Co(NH₃)₄Cl₂]⁺ complex ion?

A)2
B)3
C)4
D)4.0
E)6

Question 25

The correct name for the compound [Fe(NH₃)₅H₂O](NO₃)₂ is __________

A)pentammineaquairon(II)nitrate.
B)pentammineaquairon(III)nitrate.
C)pentammineaquaferrate(II)nitrate.
D)aquapentammineiron(II)nitrate.
E)pentamineaquadinitroiron(III).

Question 26

For the coordination compound K₃[ZrF₇],identify,in order,the charge on the complex ion,the oxidation state of the metal,and the coordination number of the metal.

A)-3,+4,7
B)-3,+7,3
C)+3,-4,7
D)+4,-7,3
E)None of these choices is correct.

Question 27

What is the coordination number of the metal atom in the complex ion in K[Pt(NH₃)Cl₅]?

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

Question 28

For the coordination compound [Zn(NH₃)₄]Cl₂,identify,in order,the charge on the complex ion,the coordination number of the metal,and the number of counter ions present.

A)-2,4,2
B)+2,4,4
C)+4,6,0
D)+4,4,2
E)None of these choices is correct.

Question 29

How many ions are formed when [Co(NH₃)₅Cl]Cl₂ dissolves in water?

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

Question 30

What is the coordination number for copper in the compound K₂[CuCl₄]?

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

Question 31

For the coordination compound K₃[Fe(CN)₆],identify,in order,the charge on the complex ion,the oxidation state of the metal,and the coordination number of the metal.

A)3+,-3,6
B)0,0,6
C)-3,+3,3
D)-3,+3,6
E)None of these choices is correct.

Question 32

What is the chemical formula of aminetrichloroplatinate(II)?

A)[Pt₂(NH₃)Cl₃]^-
B)[Pt(NH₃)₃Cl]^-
C)[Pt(NH₃)Cl₃]^2-
D)[Pt(NH₃)Cl₃]⁺
E)[Pt(NH₃)Cl₃]^-

Question 33

The correct name for K₂[CuCl₄] is __________

A)potassium copper chloride.
B)potassium tetrachlorocuprate(II).
C)dipotassium chlorocuprate(II).
D)potassium tetrachlorocopper(II).
E)dipotassium tetrachlorocopper(II).

Question 34

What is the coordination number for [Pt(NH₃)₄]Cl₂?

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

Question 35

Which of the following releases the most ions when dissolved in water?

A)[Co(NH₃)₄Cl₂](NO₃)₂
B)[Ni(NH₃)₅(H₂O)]Cl₂
C)Pt(NH₃)₃Cl₄
D)K₃[Fe(C₂O₄)₃]
E)Na₄[Fe(CN)₆]

Question 36

The correct name for [Co(NH₃)₅Cl]Cl₂ is __________

A)chloropentamminecobalt(III)chloride.
B)pentamminechlorocobalt(II)chloride.
C)pentamminechlorocobalt(III)chloride.
D)pentamminechlorocobaltate(III)chloride.
E)pentamminedichlorocobalt(III).

Question 37

What is the coordination number for Ni(CN)₄^2-?

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

Question 38

The correct name for [Co(NH₃)₆][Cr(CN)₆] is __________

A)cobaltammine chromiumcyanide.
B)hexamminecobalt(III)hexacyanochromate(II).
C)hexamminecobaltate(III)hexacyanochromium(III).
D)hexamminecobalt(III)hexacyanochromate(III).
E)hexamminecobalt(II)hexacyanochromate(III).

Question 39

The correct formula for the complex ion tetracyanoplatinate(II)is __________

A)[Pt(CN)₄²⁺].
B)[Pt(CN)₄]^2-.
C)Pt(CN)₄.
D)[Pt₂(CN)₄].
E)4[Pt(CN)]⁺.

Question 40

What is the correct formula for hexamminecobalt(III)nitrite?

A)[Co(NH₃)₆](NO₃)₃
B)Co(NH₃)₆(NO₂)₃
C)[Co(NH₃)₆](NO₂)₃
D)[Co(NH₃)₆](NO₂)₂
E)[Co(NH₃)₆](NO₃)₂

Question 41

Oxalic acid is a dicarboxylic acid with the structure HOOCCOOH.How many coordination sites does the ion (OOCCOO)^2- have?

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

Question 42

Which of the following is a polydentate ligand?

A)NO₂^-
B)OH^-
C)H₂O
D)C₂O₄^2-
E)CN^-

Question 43

Which one of the following compounds is called diamminetriaquahydroxochromium(II)nitrate?

A)[Cr(NH₃)₂(H₂O)₃(OH)](NO₃)₂
B)[Cr(NH₃)₂(H₂O)₃(OH)]NO₃
C)[Cr(NH₃)₂(H₂O)₃](OH)NO₃
D)[Cr(NH₃)₂(OH)]NO₃ • 3H₂O
E)[Cr(NH₃)₂NO₃]OH(aq)

Question 44

When a molecule of ethylenediamine replaces two molecules of NH₃ in Co(NH₃)₆³⁺,the entropy of the system __________

A)increases.
B)decreases.
C)remains the same.
D)cannot be determined.
E)is irrelevant.

Question 45

Which atoms on EDTA bond to metal ions?

A)carbon and oxygen
B)carbon and nitrogen
C)oxygen and nitrogen
D)nitrogen and hydrogen
E)oxygen and hydrogen

Question 46

The reaction,Cr(NH₃)₆³⁺(aq)+ 3 en(aq) $\leftrightarrows$ Cr(en)₃³⁺(aq)+ 6 NH₃(aq),where en represents ethylenediamine,has a small value for the enthalpy change, $\Delta$ H_rxn,yet the free-energy change is large because __________

A)the reaction rate is fast.
B)the entropy change is large and positive.
C)the enthalpy change is large enough to matter.
D)the entropy change is large and negative.
E)ethylene diamine has amino groups that are stronger bases than ammonia.

Question 47

Which is the correct formula for pentaamminecyanocobaltate(III)chloride?

A)[Co(NH₃)₅CN]Cl₂
B)[Co(NH₃)₅CN]Cl₃
C)[Co(NH₃)₅Cl](CN)₂
D)[Co(NH₃)₅CNO]Cl₂
E)[Co(NH₃)₅CNO]Cl₃

Question 48

The greater affinity of metal ions for polydentate ligands than for monodentate ligands is known as the __________ effect.

A)dentate
B)ligand
C)chelate
D)Lewis base
E)Lewis acid

Question 49

Nickel ions,Ni²⁺,should have the greatest affinity for __________

A)water.
B)ammonia.
C)chloride.
D)diethylenetriamine.
E)oxalate.

Question 50

The structure of the acetylacetonate ligand is shown.How many coordination sites does it have?

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

Question 51

The correct formula for ammonium tetracyanoplatinate(II)is __________

A)(NH₃)₂[Pt(CN)₄].
B)(NH₄)₂[Pt(CN)₄].
C)(NH₄)₂Pt(CN)₄.
D)(NH₄)₂[Pt(CN)₆].
E)NH₄[Pt(CN)₄].

Question 52

Ethylenediamine is an example of a __________ ligand.

A)tridentate
B)hexadentate
C)bidentate
D)pentadentate
E)hydrocarbon

Question 53

Which is the correct formula for potassium hexacyanoferrate(II)?

A)K[Fe(CN)₂]
B)K₂[Fe(CN)₂]
C)K₃[Fe(CN)₆]
D)K₄[Fe(CN)₆]
E)K₆[Fe(CN)₆]

Question 54

The reaction,Cr(NH₃)₆³⁺(aq)+ 3 en(aq) $\leftrightarrows$ Cr(en)₃³⁺(aq)+ 6 NH₃(aq),where en represents ethylenediamine,has a small value for the enthalpy change, $\Delta$ H_rxn,yet the equilibrium constant for this reaction is large because __________

A)the reaction rate is fast.
B)the entropy change is large and positive.
C)the enthalpy change is large enough to matter.
D)the entropy change is large and negative.
E)the equilibrium constant does not depend on the enthalpy change.

Question 55

Given the following data,calculate the approximate value of the equilibrium constant at 298 K for the reaction,Ni(NH₃)₆²⁺(aq)+ 3 en(aq) $\leftrightarrows$ Ni(en)₃²⁺(aq)+ 6 NH₃(aq),where en represents ethylenediamine.

A)1.90 $\times$ 10^-2
B)52.7
C)3.77
D)1.44 $\times$ 10³
E)6.94 $\times$ 10^-4

Question 56

How many chelation sites and donor groups does EDTA have?

A)2
B)10
C)6
D)4
E)5

Question 57

Which of the following is a chelation agent?

A)EDTA
B)Cl^-
C)NH₂
D)SCN^-
E)CN^-

Question 58

The interaction of a metal ion with a ligand having multiple atoms able to form coordinate covalent bonds is called __________

A)coordinating.
B)clawing.
C)precipitation.
D)chelation.
E)neutralization.

Question 59

EDTA is an example of a __________ ligand.

A)tridentate
B)hexadentate
C)tetradentate
D)pentadentate
E)hydrocarbon

Question 60

What is the correct formula for sodium tetracyanodihydroxovanadate(II)?

A)Na₂[V(CN)₄(OH)₂]
B)Na₃[V(CN)₄(OH)₂]
C)Na₄[V(CN)₄(OH)₂]
D)Na[V(CN)₄(OH)₂]
E)Na₃[V(CN)₄(OH)]

Question 61

Co(NH₃)₆³⁺(aq)absorbs light in the blue region of the spectrum.The color of a solution containing this ion is __________

A)blue.
B)blue-violet.
C)violet.
D)yellow-orange.
E)red.

Question 62

When the five 3d orbitals on a metal ion experience an octahedral field in a complex,they split into __________ energy levels.

A)two
B)three
C)four
D)five
E)six

Question 63

Which of the following complexes has the smallest crystal field splitting of the d orbitals?

A)CoF₆^3-
B)Co(CN)₆^3-
C)CoBr₆^3-
D)Co(H₂O)₆³⁺
E)CoI₆^3-

Question 64

Transition metals with __________ tend to form square planar complexes.

A)d ⁸ and d ⁹ configurations
B)d ¹ and d ² configurations
C)half-filled d orbitals
D)high spin
E)no d electrons

Question 65

Complex ions with different ligands have different colors because the ligands __________

A)are different colors.
B)affect the energy levels of the lone-pair electrons on the metal.
C)have different energies for their bonding electrons.
D)affect the energy levels of the metal d orbitals.
E)have different energies for their lone-pair electrons.

Question 66

Which of the following ligands will cause the smallest crystal field splitting of the d orbitals in an octahedral complex?

A)H₂O
B)Br^-
C)NH₃
D)CN^-
E)I^-

Question 67

The d_z² and d_x²_-y² orbitals are higher in energy than the d_xy,d_xz,and d_yz orbitals in an octahedral complex because these two orbitals __________

A)do not point directly at ligands.
B)point directly at ligands.
C)occupy larger volumes than the other three orbitals.
D)are in the same plane and repel one another.
E)occupy smaller volumes than the other three orbitals.

Question 68

Which of the following complexes has the largest crystal field splitting of the d orbitals?

A)CoF₆^3-
B)Co(CN)₆^3-
C)CoBr₆^3-
D)Co(H₂O)₆³⁺
E)CoI₆^3-

Question 69

In a tetrahedral crystal field,__________

A)d_xy,d_xz,and d_yz are lower in energy than d_x²_-y² and d_z².
B)d_x²_-y² and d_z² are lower in energy than d_xy,d_xz,and d_yz.
C)d_xy,d_xz,d_yz,d_x²_-y²,and d_z² all have different energies.
D)d_xy,d_xz,d_yz,d_x²_-y²²,and d_z² all have the same energy.
E)d_xy,d_xz,and d_yz have the same energy,and d_x²_-y² and d_z² have different energies.

Question 70

Which statement describing the splitting of metal d orbitals in an octahedral field is NOT correct?

A)The d orbitals are split into two energy levels.
B)One energy level contains three orbitals.
C)One energy level contains two orbitals.
D)The d_xy,d_xz,and d_yz orbitals have the lowest energy.
E)Photons cannot produce electronic transitions from one energy level to another.

Question 71

Which d orbitals have a higher energy in an octahedral complex?

A)d_xy and d_xz
B)d_z² and d_yz
C)d_z² and d_x²_-y²
D)d_x²_-y² and d_xz
E)d_xy,d_xz,and d_yz

Question 72

Which 3d orbitals have a higher energy in an octahedral crystal field?

A)d_xy and d_xz
B)d_z² and d_yz
C)d_z² and d_x²_-y²
D)d_x²_-y² and d_xz
E)d_xy,d_xz,and d_yz

Question 73

A solution containing the ion CoF₆^3- has an absorption maximum at $\lambda$ _max = 680 nm.The color of this solution is __________

A)red.
B)green.
C)blue.
D)orange.
E)violet.

Question 74

As the value of the crystal field splitting, $\Delta$ _o,increases from one complex ion to another,__________

A)the wavelength of absorbed light increases.
B)the wavelength of absorbed light decreases.
C)the number of d electrons increases.
D)the number of d electrons decreases.
E)the color of the solution shifts from red toward blue.

Question 75

The d_xy,d_xz,and d_yz orbitals are lower in energy than the d_z² and d_x²_-y² orbitals in an octahedral complex because these three orbitals __________

A)do not point directly at ligands.
B)point directly at ligands.
C)occupy larger volumes than the other two orbitals.
D)are in the same plane and repel one another.
E)occupy smaller volumes than the other two orbitals.

Question 76

Transition metal ions often absorb visible light in promoting electrons from a ground state to an excited state.Why doesn't aluminum(III)ion have this property?

A)It does,and this fact accounts for the color of some gemstones.
B)Aluminum(III)has a noble gas configuration-that of argon.
C)Aluminum(III)has a noble gas configuration-that of neon.
D)Aluminum(III)has a filled d subshell.
E)The crystal field splitting of the d orbitals in aluminum(III)is very large.

Question 77

Given that the observed absorption maximum for the complex ion CoF₆^3- in solution is $\lambda$ _max = 700 nm,what is the value of the crystal field splitting, $\Delta$ _o?

A)3 $\times$ 10^-19 J
B)3 $\times$ 10^-28 J
C)7 $\times$ 10³⁰ J
D)3 $\times$ 10^-36 J
E)7 $\times$ 10^-19 J

Question 78

Which d orbital(s)is/are highest in energy in a tetrahedral complex?

A)d_z²
B)d_xy,d_xz,and d_yz
C)d_z² and d_x²_-y²
D)d_x²_-y²
E)d_xy and d_xz

Question 79

Which of the following ligands will cause the largest crystal field splitting of the d orbitals in an octahedral complex?

A)H₂O
B)Br^-
C)NH₃
D)CN^-
E)I^-

Question 80

Crystal field theory describes __________

A)how ligands cause the metal d orbitals to have different energies.
B)the covalent bonding in transition metal complexes.
C)how d orbitals change their shapes when ligands are present.
D)how metal s,p,and d orbitals are hybridized to bond with ligands.
E)the molecular orbitals that describe the bonding in transition metal complexes.