Deck 23: Transition Metals and Coordination Chemistry

Question 1

Which one of the following species is paramagnetic?

A)Fe³⁺
B)Cu⁺
C)Zn
D)Mg
E)Au⁺

Answer 1

Fe³⁺

Question 2

What is the oxidation number of Fe in [Fe(CN)₅]^3-?

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

Answer 2

2+

Question 3

The minimum number of unshared valence electron pairs in the ligands of a coordination compound is ________.

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

Answer 3

1

Question 4

How many ligands are there in the coordination sphere of [Co(en)₂Cl₂]⁺?

A)3
B)6
C)4
D)1
E)0

Question 5

In the compound,CaNa[Fe(CN)₆],what ligands are in the coordination sphere?

A)Ca²⁺
B)
C)CN^-
D)H₂O
E)none of the above

Question 6

The coordination number of cobalt in CoCl₃ ^∙ 6NH₃ is ________.

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

Question 7

Which one of the following is not true about transition metals?

A)They frequently have more than one common oxidation state.
B)Their compounds are frequently colored.
C)Their compounds frequently exhibit magnetic properties.
D)They are found in the d-block of the periodic table.
E)They typically have low melting points.

Question 8

Paramagnetic solids ________.

A)have atoms with one or more unpaired electrons
B)show very slight magnetic character when placed in a magnetic field
C)have atoms with randomly oriented magnetic moments
D)have atoms with strongly aligned electrons when placed in a magnetic field
E)both A and D

Question 9

What is the most common geometry found in four-coordinate complexes?

A)square planar
B)octahedral
C)tetrahedral
D)icosahedral
E)trigonal bipyramidal

Question 10

Changes in the coordination sphere of a complex compound may lead to changes in ________.

A)color
B)physical properties
C)chemical properties
D)stability
E)all of the above

Question 11

Which mineral contains titanium?

A)pyrolusite
B)chalcopyrite
C)galena
D)rutile
E)sphalerite

Question 12

A mineral is ________.

A)a solid inorganic compound that contains one or more metals
B)a vitamin
C)metal in its elemental form
D)a transition metal ion
E)a source of carbon

Question 13

The lanthanide contraction is responsible for the fact that ________.

A)Zr and Y have about the same radius
B)Zr and Nb have similar oxidation states
C)Zr and Hf have about the same radius
D)Zr and Zn have similar oxidation states
E)Zr and Hf have the same oxidation states

Question 14

Formation of a complex species of Mⁿ⁺ metal ion with ligands often ________.

A)"masks" original chemical properties of both the Mⁿ⁺ ion and the ligands
B)reduces availability of the free Mⁿ⁺ ions in solution
C)may cause changes in the ease with which Mⁿ⁺ is reduced or oxidized
D)alters original physical properties of Mⁿ⁺
E)all of the above

Question 15

What is the charge on the complex ion in Ca₂[Fe(CN)₆]?

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

Question 16

What two oxidation states are more frequently observed in the first transition series than in the third?

A)+3 and +7
B)+2 and +3
C)+2 and +7
D)+5 and +6
E)+3 and +5

Question 17

Chalcocite,chalcopyrite,and malachite are sources of which metal?

A)manganese
B)copper
C)titanium
D)iron
E)zinc

Question 18

Which of the following complexes has a coordination number of 6?

A)[Co(NH₃)₂Cl₂]
B)[Co(NH₃)₄]²⁺
C)[Co(en)₃]³⁺
D)[Co(NH₃)₂]³⁺
E)None of these complexes has coordination number 6.

Question 19

What are the respective central-metal oxidation state,coordination number,and overall charge on the complex ion in Na₂[Cr(NH₃)₂ (NCS)₄]?

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

Question 20

A substance with unpaired electrons will be ________.

A)slightly attracted to a magnet
B)slightly repelled by a magnet
C)permanently magnetic
D)brightly colored
E)nonmetallic

Question 21

What are the donor atoms in ferrichrome and how many of them are in one molecule?

A)Cr, 5
B)N, 4
C)O, 6
D)Fe, 4
E)S, 6

Question 22

What metal is complexed in chlorophyll?

A)iron
B)chromium
C)manganese
D)vanadium
E)magnesium

Question 23

Linkage isomerism would most likely occur when which of the following ligands is present?

A)H₂O
B)NH₃
C)Cl^-
D)PF₃
E)NCS^-

Question 24

A ligand with a single donor atom is called ________.

A)a chelon
B)a chelate
C)polydentate
D)monodentate
E)bidentate

Question 25

What form of hemoglobin is purplish-red?

A)myoglobin
B)deoxyhemoglobin
C)heme
D)oxyhemoglobin
E)none of the above

Question 26

How many bonds can ethylenediamine form to a metal ion?

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

Question 27

Which one of the following species is a potential polydentate ligand (chelating agent)?

A)NH₃
B)
C)
D)H₂O
E)C₂O₄^2-

Question 28

The coordination number and oxidation number of the central atom in [Fe(H₂O)₄Cl₂] are ________ and ________,respectively.

A)4, +1
B)6, +1
C)6, +2
D)5, +2
E)4, +2

Question 29

In humans,what percent of absorbed iron is found in blood?

A)15
B)25
C)40
D)60
E)75

Question 30

Which of the following is not a chelating agent?

A)chloride anion
B)EDTA
C)porphine
D)ethylenediamine
E)oxalate anion

Question 31

What is the purpose of adding EDTA to prepared foods?

A)to keep ions such as Ca²⁺ in solution so the foods look good
B)to complex trace metal ions that catalyze decomposition reactions
C)to complex iron (III)ions so they can catalyze protein decomposition on cooking
D)to aid in browning of the surface during cooking
E)to prevent dissolution of the container in the food when stored for long periods of time

Question 32

Isomers whose ligands can bind directly to a metal or be outside the lattice are called ________.

A)linkage isomers
B)rotational isomers
C)coordination sphere isomers
D)geometric isomers
E)optical isomers

Question 33

Which one of the following is the correct formula for potassium diaquatetrachloromolybdate (III)?

A)K₂[Mo(H₂O)₂Cl₄]
B)K[Mo(H₂O)₂Cl₂]Cl₂
C)K[Mo(H₂O)₂Cl₄]
D)Mo[K(H₂O)₂]Cl₄
E)K₃[Mo(H₂O)₂Cl₄]

Question 34

Based on entropy considerations alone,which homogeneous aqueous equilibrium would be expected to lie to the right?

A)AgI₂^- + 2Br^- ⇔ AgBr₂^- + 2I^-
B)Ni(H₂NC₂H₄NH₂)₃²⁺ + 6NH₃ ⇔ Ni(NH₃)₆²⁺ + 3H₂NC₂H₄NH₂
C)CoCl₄²⁺ + 6H₂O ⇔ Co(H₂O)₆²⁺ + 4Cl^-
D)Fe(NH₃)₆²⁺ + C₂₀H₁₀N₄^2- ⇔ Fe(NH₃)₂(C₂₀H₁₀N₄)+ 4NH₃
E)Cu(NH₃)₄²⁺ + 6H₂O ⇔ Cu(H₂O)₆²⁺ + 4NH₃

Question 35

The chelate effect is best attributed to considerations of which type?

A)hydration
B)enthalpy
C)entropy
D)hydrogen bonding
E)resonance

Question 36

What are the donor atoms in a porphine molecule?

A)N
B)O
C)S
D)Br
E)F

Question 37

Does either or both cis- or trans-[Mn(en)₂Br₂] have optical isomers?

A)cis only
B)trans only
C)both cis and trans
D)neither cis nor trans
E)[Mn(en)₂Br₂] does not exhibit cis-trans isomerism.

Question 38

A complex of correctly written formula [Pt(NH₃)₃Br]Br ∙ H₂O has which set of ligands in its inner coordination sphere?

A)3 NH₃
B)3 NH₃ and 2 Br^-
C)3 NH₃ and 1 Br^-
D)3 NH₃, 1 Br^-, and 1 H₂O
E)3 NH₃, 2 Br^-, and 1 H₂O

Question 39

Which of the following is a polydentate ligand?

A)ammonia
B)oxalate ion
C)chloride ion
D)water
E)hydroxide ion

Question 40

Which of the following will display optical isomerism?

A)square-planar [Rh(CO)₂Cl₂]^-
B)square-planar [Pt(H₂NC₂H₄NH₂)₂]²⁺
C)octahedral [Co(NH₃)₆]³⁺
D)octahedral [Co(NH₃)₅Cl]²⁺
E)octahedral [Co(H₂NC₂H₄NH₂)₃]³⁺

Question 41

Using the following abbreviated spectrochemical series,determine which complex ion is most likely to absorb light in the red region of the visible spectrum. small splitting Cl^- < H₂O < NH₃ < CN^- large splitting

A)[CuCl₄]^2-
B)[Cu(H₂O)₄]²⁺
C)[Cu(NH₃)₄]²⁺
D)[Cu(CN)₄]^2-
E)not enough information given to determine

Question 42

A metal complex absorbs light mainly at 420 nm.What is the color of the complex?

A)green
B)yellow
C)red
D)orange
E)purple

Question 43

Which one of the following complexes would most likely have tetrahedral geometry?

A)[NiCl₄]^2-
B)[Co(H₂O)₆]²⁺
C)[Cr(NH₃)₆]³⁺
D)[Fe(CN)₆]³⁺
E)[Pt(NH₃)₂Cl₂]

Question 44

Complexes containing metals with which one of the following electron configurations are usually white/colorless?

A)d²
B)d¹
C)d⁵
D)d⁸
E)d¹⁰

Question 45

Which of the following cannot form both high- and low-spin octahedral complexes?

A)Mn²⁺
B)V²⁺
C)Co³⁺
D)Cr²⁺
E)All of the above can form both high- and low-spin complexes.

Question 46

Which of the following ions can form both a high spin and a low spin octahedral complexes?

A)Fe³⁺ and Co²⁺ only
B)Fe³⁺, Mn³⁺, and Co²⁺
C)Cr³⁺ only
D)Fe³⁺, Cr³⁺, and Co²⁺
E)Mn³⁺, Cr³⁺, and Co²⁺

Question 47

Consider a complex in which manganese (III)is bonded to six identical ligands.Which one of the following ligands will result in the smallest value of Δ?

A)
B)NH₃
C)H₂O
D)F^-
E)CN^-

Question 48

The attraction of a metal to a neutral ligand is due to ________ bonding.

A)ionic
B)covalent
C)ion-dipole
D)dipole-dipole
E)hydrophobic

Question 49

Which one of the following complex ions will be paramagnetic?

A)[Fe(H₂O)₆]²⁺ (low spin)
B)[Fe(H₂O)₆]³⁺ (low spin)
C)[Co(H₂O)₆]³⁺ (low spin)
D)[Zn(H₂O)₄]²⁺
E)[Zn(NH₃)₄]²⁺

Question 50

Which of the following statements is (are)false?

A)The greater the energy gap in a metal complex, the shorter the wavelength of light the complex will absorb.
B)Complex color depends on both the metal and the ligand.
C)Metal complexes with an ammonia ligand have a larger energy gap than the corresponding fluoride complexes.
D)Strong field ligands are associated with low energy gaps.
E)Both A and C

Question 51

A racemic mixture is ________.

A)an equal mixture of both enantiomers of an optically active species
B)a mixture of an optically active species with an optically inactive species
C)an equal mixture of cis- and trans-isomers
D)a mixture of metal ions and ligands in equilibrium
E)a mixture of structural isomers

Question 52

Which one of the following substances has three unpaired d electrons?

A)[Zn(NH₃)₄]²⁺
B)[V(H₂O)₆]⁴⁺
C)[Ag(NH₃)₂]⁺
D)[Cu(NH₃)₄]²⁺
E)[Cr(CN)₆]^3-

Question 53

Complexes containing metals with d¹⁰ electron configurations are typically white/colorless because ________.

A)there is no d electron that can be promoted via the absorption of visible light
B)the empty d orbitals absorb all of the visible wavelengths
C)there are no d electrons to form bonds to ligands
D)a complex must be charged to be colored
E)d electrons must be emitted by the complex in order for it to appear colored

Question 54

Complexes containing metals with d¹⁰ electron configurations are typically ________.

A)violet
B)blue
C)green
D)yellow
E)white/colorless

Question 55

Coordination sphere isomers ________.

A)have the same molecular formula and coordination number
B)have the same molecular formula but different coordination numbers
C)have different molecular formulas but the same coordination number
D)have different molecular formulas and different coordination numbers
E)are the same as resonance structures

Question 56

A complex that absorbs light at 700 nm will appear ________.

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

Question 57

Based on the crystal-field strengths F^- < CH₂CN < NH₃ < NO₂^- < CN^-,which Co (III)complex is most likely high-spin?

A)[Co(NH₃)₆]³⁺
B)[Co(NO₂)₆]^3-
C)[Co(CN)₆]^3-
D)[CoF₆]^3-
E)[Co(CH₃CN)₆]³⁺

Question 58

Based on the crystal-field strengths Cl^- < F^- < H₂O < NH₃ < H₂NC₂H₄NH₂,which octahedral complex below has its d-d electronic transition at shortest wavelength?

A)[Ti(NH₃)₆]³⁺
B)[Ti(H₂NC₂H₄NH₂)₃]³⁺
C)[Ti(H₂O)₆]³⁺
D)[TiCl₆]^3-
E)[TiF₆]^3-

Question 59

Which one of the following complexes can exhibit geometrical isomerism?

A)[Pt(NH₃)₂Cl₂] (square planar)
B)[Zn(NH₃)₂Cl₂] (tetrahedral)
C)[Cu(NH₃)₄]²⁺ (square planar)
D)[Cu(NH₃)₅Cl]²⁺ (octahedral)
E)All of the above can exhibit geometrical isomerism.

Question 60

Which compound is most likely white/colorless?

A)[Cu(H₂O)₄]²⁺
B)[Ni(H₂O)₆]²⁺
C)[Cr(H₂O)₅Cl]²⁺
D)[Cd(H₂O)₄]²⁺
E)[Co(H₂O)₆]²⁺

Question 61

What is the oxidation state of iron in CaNa[Fe(CN)₆]?

A)0
B)+2
C)+3
D)+4
E)+6

Question 62

How many d electrons are in the iron ion of K₃[Fe(CN)₆]?

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

Question 63

The coordination number of platinum in complexes is always ________.

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

Question 64

How many d electrons are associated with the metal ion in [Cr(NH₃)₃⁺?

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

Question 65

What is the charge of the central metal ion in Ca₃[Fe(CN)₆]₂?

A)0
B)1+
C)2+
D)3+
E)6+

Question 66

What is the coordination number of iron in CaNa[Fe(CN)₆]?

A)2
B)8
C)4
D)6
E)12

Question 67

During the formation of a coordination compound,the ________ acts as a Lewis base.

A)metal
B)ligand

Question 68

The charge of the complex ion in [Zn(H₂O)₃Cl]Cl ________.

A)0
B)1-
C)2+
D)1+
E)2-

Question 69

What is the oxidation number of cobalt in [Co(NH₃)₄F₂]?

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

Question 70

What is the oxidation number of chromium in Cr[(NH₃)₄Cl₂]Cl?

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

Question 71

In the following reaction,Ni²⁺ is acting as a(n)________. Ni²⁺ (g)+ 6H₂O (l)→ Ni(H₂O)₆²⁺ (aq)

A)oxidizing agent
B)Lewis acid
C)precipitating agent
D)solvent
E)ligand

Question 72

The coordination sphere of a complex consists of ________.

A)the central metal ion only
B)the ligands
C)the central metal ion and the ligands bonded to it
D)the primary and secondary valencies
E)coordination and steric numbers

Question 73

During the formation of a coordination compound,the ________ acts as a Lewis acid.

A)metal
B)ligand

Question 74

What is the coordination number of cobalt in [Co(NH₃)₅Cl](NO₃)₂?

A)12
B)8
C)4
D)2
E)6

Question 75

What is the ligand in Ca₃[Fe(CN)₆]₂?

A)Ca²⁺
B)Fe³⁺
C)CN^-
D)Fe(CN)₆^3-
E)Fe²⁺

Question 76

The coordination number for [Zn(H₂O)₃Cl]Cl is ________.

A)5
B)4
C)2
D)1
E)6

Question 77

The coordination numbers of cobalt (III)and of chromium (III)in their complexes are always ________.

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

Question 78

What is the charge on the complex ion in Mg₂[FeCl₆]?

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

Question 79

Which of the following can form both high- and low-spin octahedral complexes?

A)Cr²⁺
B)Cr³⁺
C)Zn²⁺
D)Cu⁺
E)All of the above can form either high- or low-spin complexes.

Question 80

What is the oxidation state of iron in K₃[Fe(CN)₆]?

A)0
B)+2
C)+3
D)+4
E)+6