Deck 22: Metal Complexes

Question 1

Which statement below about ligands that form coordination complexes with transition metals is false?

A)A ligand that attaches itself to a metal ion is acting as a Lewis acid.
B)Neutral molecules can function as ligands and can form coordination complexes with transition metal ions.
C)Anions can function as ligands and can form coordination complexes with transition metal ions.
D)The ligand in a coordination complex contains a particular atom which functions as the donor atom.
E)The bond between the ligand and the transition metal ion in a coordination complex is a coordinate covalent bond.

Answer 1

A ligand that attaches itself to a metal ion is acting as a Lewis acid.

Question 2

Which of the following is true of all ligands?

A)Ligands can only form one bond with a metal ion.
B)Stronger ligands have a larger diameter.
C)Ligands must contain elements that have a very low electronegativity.
D)Ligands act as a Lewis base when they attach to a metal ion.
E)Ligands are electron deficient.

Answer 2

Ligands act as a Lewis base when they attach to a metal ion.

Question 3

The number of possible donor atoms in the EDTA^4- (ethylenediaminetetraacetate)ligand is:

A)2
B)3
C)4
D)6
E)8

Answer 3

6

Question 4

The number of possible donor atoms in each bidentate ligand, C₂O₄^2-, in the [Fe(C₂O₄)₃]^3- coordination complex ion is:

A)2
B)3
C)4
D)6
E)8

Question 5

The charge on the metal ion in the coordination complex ion, [Co(CO₃)₃]³, is:

A)0
B)2+
C)3
D)3+
E)6

Question 6

A coordination compound formed from cobalt(III)sulfate and ammonia contains six ammonia molecules as ligands. The formula of the compound is

A)Co₂(SO₄)₃.6NH₃
B)[Co(NH₃)₆]₂(SO₄)₃
C)Co₃SO₄(NH₃)₆
D)Co₂(SO₄)₃(NH₄)₆
E)Co₂[(NH₃)₆](SO₄)₃

Question 7

A coordination compound formed from chromium(III)chloride contains five ammonia molecules and one water molecule, which function as ligands. The coordination compound's formula is:

A)[Cr(NH₃)₅(H₂O)]Cl₃
B)Cr₃Cl(NH₃)₅H₂O
C)CrCl₃.5NH₃.H₂O
D)Cr(NH₃)₅Cl₃.H₂O
E)[Cr(NH₃)₅]Cl₃.H₂O

Question 8

A compound contains a transition metal coordination complex. This coordination complex consists of one iron(III)ion with three C₂O₄^2- ions attached as ligands. Which formula below describes a compound that fits this description?

A)K₃[Fe(C₂O₄)₃]
B)Fe(C₂O₄)₃
C)[Fe(C₂O₄)₃]Cl₃
D)Fe(C₂O₄)₃](SO₄)₃
E)Ca₃[Fe(C₂O₄)₃]

Question 9

A complex ion is formed by a Co³⁺ ion, which is linked to one carbonate ion and four ammonia molecules. Which formula correctly represents a salt of this complex ion?

A)Na₃[Co(NH₃)₄CO₃]
B)Na[Co(NH₃)₄CO₃]
C)[Co(NH₃)₄CO₃]CO₃
D)[Co(NH₃)₄CO₃]Cl₂
E)[Co(NH₃)₄CO₃]₂SO₄

Question 10

A compound contains a transition metal coordination complex. This coordination complex consists of one cobalt(III)ion with five ammonia molecules and one cyanide ion attached as ligands. Which formula correctly describes a compound that would fit the description?

A)K₄[CoCN(NH₃)₅]
B)K₂[CoCN(NH₃)₅]
C)[CoCN(NH₃)₅](SO₄)₂
D)[CoCN(NH₃)₅]SO₄
E)[CoCN(NH₃)₅]Cl₃

Question 11

A compound contains a transition metal coordination complex. This coordination complex consists of one iron(III)ion with 3 ammonia molecules, one ethylenediamine (en)molecule, and one cyanide ion attached as ligands. Which formula correctly describes a compound that would fit the description?

A)K₄[FeCN(NH₃)₃(en)₂]
B)K₂[FeCN(NH₃)₃(en)]
C)[Fe(CN)₂(NH₃)₅(en)₂](SO₄)₂
D)[FeCN(NH₃)₃(en)₂]SO₄
E)[Fe(en)CN(NH₃)₃]Cl₃

Question 12

Which coordination complex would you expect to be the most stable?

A)Co(NH₃)₆³⁺
B)CoF₆³
C)Co(en)₃³⁺
D)Co(dien)₂³⁺ dien = H₂N-CH₂-CH₂-NH-CH₂-CH₂-NH₂
E)Co(EDTA)EDTA = ethylenediaminetetraacetate

Question 13

Which of the following ligands would be the most difficult to remove from an iron(III)cation under similar conditions?

A)NH₃
B)F
C)en
D)O₂
E)EDTA^4-

Question 14

EDTA^4- (ethylenediaminetetraacetate anion), shown below, is capable of acting as a ________ ligand.

A)monodentate
B)bidentate
C)tridentate
D)tetradentate
E)polydentate

Question 15

How many donor atoms are on a monodentate ligand?

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

Question 16

How many donor atoms are on a bidentate ligand?

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

Question 17

How many bonds can a polydentate ligand form with a metal cation?

A)0
B)1
C)2
D)4
E)both C and D are possible

Question 18

Which species can function as a chelating ligand?

A)NH₃
B)NH₄⁺
C)CN^-
D)CH₃-CH₂-CH₂-NH₂
E)NH₂-CH₂-CH₂-NH₂

Question 19

Which species can function as a chelating ligand?

A)NH₃
B)NH₄⁺
C)CN^-
D)CH₃-CH₂-CH₂-O-H
E)NH₂-CH₂-CH₂-NH-CH₃

Question 20

Which cobalt complex should be the most stable (having the largest formation constant)?

A)Co(NH₃)₆²⁺
B)Co(NH₃)₆³⁺
C)Co(H₂O)₆²⁺
D)Co(F)₆^3-
E)Co(en)₃³⁺

Question 21

The name for the complex ion, [Ni(CN)₄]², is:

A)tetracyanonickel(II)
B)nickel(II)tetracyanide
C)tetracyanonickelo(II)
D)tetracyanonickelate(II)
E)tetracyanonickelite(II)

Question 22

The name for the complex ion, [Co(NH₃)₆]³⁺, is

A)cobalt hexammine.
B)cobalt(III)hexamine.
C)hexamminecobaltate(III).
D)hexaminocobaltate(III).
E)hexamminecobalt(III).

Question 23

The name for the transition metal complex [Fe(CN)₆]^3- is

A)hexacyano ferrate(III).
B)hexacyanoiron(II).
C)iron(III)hexacyanide.
D)ferrous cyanide.
E)ferric cyanide.

Question 24

The name for the transition metal complex [Cr(H₂O)₆]Cl₃ is

A)hexawaterchromium(III)chloride.
B)hexaaquachromium(III)trichloride.
C)hexaaquachromium(III)chloride.
D)chromium(III)aqua chloride.
E)chromium(III)chloride hexahydrate.

Question 25

The correct name for the transition metal complex [CoCl₃(NH₃)₃] is

A)cobalt(III)chloride triammine.
B)triamminetrichlorocobalt(III).
C)triamminetrichlorocobalt(II).
D)cobalt ammonia chloride.
E)cobalt(III)ammonium chloride.

Question 26

The name for the complex ion, [AuCl₄], is

A)gold tetrachloride.
B)gold(II)tetrachloride.
C)auric tetrachloride.
D)tetrachlorogold(III).
E)tetrachloroaurate(III).

Question 27

The correct name for the compound, [CrCl₂(en)₂]₂C₂O₄, is

A)dichlorobis(ethylenediamine)chromium(III)oxalate.
B)bis(ethylenediamine)dichlorochromate(III)oxalate.
C)dichlorobis(ethylenediamine)oxalatochromium(III).
D)dichlorobis(ethylenediamine)oxalatochromate(III).
E)bis(dichlorobis(ethylenediamine)chromium(III))oxalate.

Question 28

The compound, [Co(NH₃)₆]₂[PtCl₄]₃, is named

A)cobalt(III)hexammine tetrachloroplatinate(II).
B)cobalt(II)hexammine tetrachloroplatinate(II).
C)cobalt(III)hexammine platinum(II)tetrachloride.
D)hexamminecobalt(III)tetrachloroplatinate(II).
E)hexamminecobalt(III)platinum(II)tetrachloride.

Question 29

The compound, (NH₄)₃[FeF₆], is named

A)ammonium hexafluoroiron(III).
B)ammonium hexafluoroferrate(III).
C)ammonium iron(III)hexafluoride.
D)hexafluoroiron(III)ammonium.
E)triammonium hexafluoroiron(III).

Question 30

The coordination complex, [Co(NO₂)(NH₃)₅]Cl₂, is named

A)pentaamminenitrocobalt(III)chloride.
B)pentaamminenitritocobalt(II)chloride.
C)pentaamminenitrocobalt(II)chloride.
D)pentaamminenitritocobalt(III)chloride.
E)nitropentaamminecobalt(II)chloride.

Question 31

The coordination complex, [Co(NO₂)(NH₃)₅]Cl₂, is named

A)pentaamminenitrocobalt(III)chloride.
B)pentaamminenitritocobalt(II)chloride.
C)pentaamminenitrocobalt(II)chloride.
D)pentaamminenitritocobalt(III)chloride.
E)nitropentaamminecobalt(II)chloride.

Question 32

The metal complex, [Cr(en)₃]Cl₃, is named

A)tri(ethylenediamine)chromium(III)trichloride.
B)tri(ethylenediamine)chromium(III)chloride.
C)trichloro ethylenediaminechromate(III).
D)tris(ethylenediamine)chromium(III)chloride.
E)bis(ethylenediamine)chromium(III)trichloride.

Question 33

The complex ion, [Cr(dien)₂]³⁺ is shown below. The coordination number of the chromium ion in the [Cr(dien)₂]³⁺ is: dien =

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

Question 34

The coordination number of Ag, in the following complex, is:

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

Question 35

The coordination number of platinum in the complex ion, [Pt(C₂O₄)₂]², is:

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

Question 36

The coordination number of platinum in the complex ion in the compound, [Pt(NH₃)₄]SO₄, is:

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

Question 37

The coordination number of the cobalt ion in the coordination complex ion present in [Co(Cl)(NH₃)₄(H₂O)]Cl₂, is:

A)3
B)4
C)5
D)6
E)8

Question 38

The coordination number of the nickel ion in the complex ion,

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

Question 39

The coordination number of the cobalt ion in the complex ion in the [Co(Cl)(NH₃)₅]Cl₂ compound is:

A)1
B)3
C)5
D)6
E)8

Question 40

Cu²⁺ ion reacts with ammonia molecules to form the Cu(NH₃)₄²⁺ ion.Which statement below is true?

A)The copper ion is functioning as a Lewis base.
B)The ammonia molecule is functioning as an acceptor molecule.
C)The bond between the ammonia and the copper(II)ion is an ionic bond.
D)The ammonia molecule is a monodentate ligand.
E)The copper(II)ion is a 6-coordinate species in this complex ion.

Question 41

The correct name of the neutral coordination complex shown below is

A)cisdiaminodichloroplatinate(II).
B)cisdiaminodichloroplatinum(II).
C)cisdiamminedichloroplatinum(II).
D)transdiaminodichloroplatinum(II).
E)transdiamminedichloroplatinum(II).

Question 42

A platinum coordination complex has the formula, [PtCl(NH₃)₂Br], and exhibits a square planar geometry. How many geometric isomers of this compound should exist?

A)1 (no isomers)
B)2
C)3
D)4
E)5

Question 43

A platinum coordination complex has the formula, [Pt(Br)(Cl)(I)(NH₃ )], and exhibits a square planar geometry. How many geometric isomers of this compound should exist?

A)1 (no isomers)
B)2
C)3
D)4
E)5

Question 44

A platinum coordination complex has the formula, [PtBr(CN)₃]⁺, and exhibits a square planar geometry. How many geometric isomers of this compound should exist?

A)1 (no isomers)
B)2
C)3
D)4
E)5

Question 45

A coordination complex in which the ligands exhibit an octahedral geometry about the central metal ion has the formula, [CoCl₂(NH₃)₄]. How many geometric isomers of this compound should exist?

A)1 (no isomers)
B)2
C)3
D)4
E)5

Question 46

A coordination complex in which the ligands exhibit an octahedral geometry about the central metal ion has the formula, [CoCl₃(NH₃)₃]^-. How many geometric isomers of this compound should exist?

A)1 (no isomers)
B)2
C)3
D)4
E)5

Question 47

Which complex ion is a chiral isomer?

A)square planar [Pt(en)₂]²⁺
B)tetrahedral [NiCl₄]²
C)octahedral [Co(en)₃]³⁺
D)octahedral [Co(NH₃)₄Cl₂]⁺
E)square planar [Pt(NH₃)ClBrI]

Question 48

A coordination complex in which the ligands exhibit an octahedral geometry about the central metal ion has the formula, [CrCl₂(en)₂]⁺. How many geometric isomers of this compound should exist?

A)1 (no isomers)
B)2
C)3
D)4
E)5

Question 49

A coordination complex in which the ligands exhibit an octahedral geometry about the central metal ion has the formula, [CrCl₂(en)₂]⁺. How many isomers of this complex ion should exist?

A)1 (no isomers)
B)2
C)3
D)4
E)5

Question 50

The splitting of the d-orbitals of transition metals by a particular complex geometry gives rise to the pattern: ? Which one of the following geometries produces the splitting pattern seen above?

A)linear
B)octahedral
C)planar triangular
D)square planar
E)tetrahedral

Question 51

A complex ion which has its absorption maximum in the blue region of the visible spectrum would appear to be ________ in color.

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

Question 52

A complex ion which has its absorption maximum in the red region of the visible spectrum would appear to be ________ in color.

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

Question 53

Many coordination complexes are colored due to absorption of light in the visible region of the spectrum. Which one of the following coordination complexes of transition metals is not expected to be a colored complex?Hint: Electrons transitioning between occupied and unoccupied d-orbitals produce colors in metal complexes.

A)Co(NH₃)₆³⁺
B)Cr(NH₃)₆²⁺
C)Cu(NH₃)₄²⁺
D)V(H₂O)₆³⁺
E)Zn(NH₃)₄²⁺

Question 54

The following order is observed in the spectrochemical series for ligands CN^- > NO₂^- > en > NH₃ > H₂O > C₂O₄^2- > OH^- > F^- > Cl^- > Br^- > I^- Based on this series, which of the following would absorb the highest energy light?

A)[Fe(NH₃)₆]²⁺
B)[Fe(NH₃)₆]³⁺
C)[Os(CN)₆]^4-
D)[Os(NH₃)₆]²⁺
E)[Fe(CN)₆]^3-

Question 55

The following order is observed in the spectrochemical series for ligands CN^- > NO₂^- > en > NH₃ > H₂O > C₂O₄^2- > OH^- > F^- > Cl^- > Br^- > I^- Based on this series, which of the following would absorb the highest energy light?

A)[Os(NH₃)₆]²⁺
B)[Os(NH₃)₆]⁴⁺
C)[Os(H₂O)₆]⁴⁺
D)[Os(H₂O)₆]²⁺
E)[Os(Br)₆]^3-

Question 56

A Mo²⁺ ion has ________ 4d electrons.

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

Question 57

The following order is observed in the spectrochemical series for ligands CN^- > NO₂^- > en > NH₃ > H₂O > C₂O₄^2- > OH^- > F^- > Cl^- > Br^- > I^- It was observed that for the two 6-coordinate cobalt complexes, CoF₆³ and Co(NH₃)₆³⁺, one is diamagnetic and one is paramagnetic. How many unpaired electrons are there in the paramagnetic complex ion?

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

Question 58

The following order is observed in the spectrochemical series for ligands CN^- > NO₂^- > en > NH₃ > H₂O > C₂O₄^2- > OH^- > F^- > Cl^- > Br^- > I^- How many unpaired electrons would you expect to find in the complex ion, Cr(CN)₆³ if the value of the splitting parameter is as large as it is in typical cyanide complexes?

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

Question 59

The following order is observed in the spectrochemical series for ligands CN^- > NO₂^- > en > NH₃ > H₂O > C₂O₄^2- > OH^- > F^- > Cl^- > Br^- > I^-Cr(NH₃)₆³⁺ and Ni(NH₃)₆²⁺ are both positively charged coordination complexes. Which statement describes the magnetic properties of the complexes?

A)Cr(NH₃)₆³⁺ and Ni(NH₃)₆²⁺ are both diamagnetic.
B)Cr(NH₃)₆³⁺ is diamagnetic while Ni(NH₃)₆²⁺ is paramagnetic.
C)Cr(NH₃)₆³⁺ is paramagnetic while Ni(NH₃)₆²⁺ is diamagnetic.
D)Both complex ions are paramagnetic, but Cr(NH₃)₆³⁺ has a larger number of unpaired electrons than Ni(NH₃)₆²⁺ hence its paramagnetism is more pronounced.
E)Both complex ions are paramagnetic, but Ni(NH₃)₆²⁺ has a larger number of unpaired electrons than Cr(NH₃)₆³⁺ hence its paramagnetism is more pronounced.

Question 60

When bound to oxygen, the iron(II)found in a heme group has what coordination number?

A)2
B)4
C)5
D)6
E)8

Question 61

The heme found in cyanocobalamin, otherwise known as vitamin B₁₂, contains what metal ion?

A)Fe(II)
B)Fe(III)
C)Co(II)
D)Cr(III)
E)Cu(II)

Question 62

Heme groups contain a porphyrin structure as a part of their structure. The donor atoms in a porphyrin structure are composed of what element?

A)Oxygen
B)Nitrogen
C)Carbon
D)Iron
E)Sulfur

Question 63

The iron found in hemoglobin serves what purpose?

A)It holds together the structure.
B)It oxidizes bacteria found in the blood, killing them.
C)It converts oxygen into carbon dioxide.
D)It bonds to oxygen and allows the blood to carry oxygen throughout the body.
E)It allows hemoglobin to bond to DNA, helping to protect the DNA from damage.

Question 64

A bidentate ligand has ________ donor atom(s).

Question 65

A monodentate ligand has ________ donor atom(s).

Question 66

Ligands act as Lewis ________ when they react with a metal cation and form a bond.

Question 67

The equilibrium constant expression obtained for the process
Cu²⁺(aq)+ 4NH₃(aq) Cu(NH₃)²⁺(aq)is[Cu(NH₃)₄²⁺]/[Cu²⁺][NH₃]⁴. This expression is called the ________ constant.

Question 68

A compound contains a transition metal coordination complex. This coordination complex consists of one Ni(II)ion with 2 water molecules, two ethylenediamine (en)molecules, and the remaining positions filled with Cl ions acting as ligands. Write the correct formula for this complex ion with the correct charge.

Question 69

A compound contains a transition metal coordination complex. This coordination complex consists of one Cu(I)ion, complexed with two water molecules, one ethylenediamine molecule, and Cl ions in the remaining ligand positions. Write the correct formula for this complex ion, including the correct charge.

Question 70

Write the correct formula for the metal complex with the name potassium hexacyanoferrate(III).

Question 71

Write the correct formula for the metal complex with the name ammonium diaquatetrachlorocobaltate(II).

Question 72

Write the correct name for the metal complex Na[Co(NO₂)₆].

Question 73

Write the correct name for the metal complex [Pt(en)₂Cl₂](NO₃)₂.

Question 74

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

Question 75

The ethylenediamine molecule (en), functions as a bidentate ligand and forms a coordination complex with platinum: [Pt(en)₂]²⁺. What is the coordination number to the platinum(II)ion in this coordination complex?

Question 76

The ethylenediamine molecule (en), functions as a bidentate ligand and forms a coordination complex with cobalt: [Co(en)₂(H₂O)₂]³⁺. Assign a coordination number and a charge to the cobalt ion in this coordination complex.

Question 77

Give the names of both isomers of Pt(NH₃)₂Br₂.

Question 78

In the coordination complex [Ag(NH₃)₂]Br, the coordination number and oxidation number of the central atom are ________.

Question 79

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

Question 80

In the coordination complex [Co(NH₃)₂(H₂O)₂Cl₂]⁺, the coordination number and oxidation number of the central atom are ________.