Deck 23: Transition Metals and Coordination Chemistry

Question 1

Diamagnetic solids ________.

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

Answer 1

show very slight magnetic character when placed in a magnetic field

Question 2

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

Answer 2

all of the above

Question 3

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

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

Answer 3

2+

Question 4

Which mineral contains titanium?

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

Question 5

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 6

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 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

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

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

Question 9

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

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

Question 10

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 11

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

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

Question 12

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

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

Question 13

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 14

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 15

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

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

Question 16

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

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

Question 17

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

Question 18

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

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

Question 19

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 20

Which one of the following species is paramagnetic?

A)Cu⁺
B)Cr³⁺
C)Zn
D)Ca
E)Ag⁺

Question 21

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 22

A ligand with a single donor atom is called ________.

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

Question 23

What form of hemoglobin is purplish-red?

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

Question 24

How many bonds can ethylenediamine form to a metal ion?

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

Question 25

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

A)NH₃
B)Cl^-
C)CN^-
D)H₂O
E)C₂O₄^2-

Question 26

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

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

Question 27

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

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

Question 28

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 29

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 30

What metal is complexed in chlorophyll?

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

Question 31

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 32

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 33

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 34

The coordination number and oxidation number of the central atom in [Mn(CO)₄Br₂] are ________ and ________, respectively.

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

Question 35

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 36

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 37

Which of the following is not a chelating agent?

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

Question 38

Which of the following is a polydentate ligand?

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

Question 39

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 40

What are the donor atoms in a porphine molecule?

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

Question 41

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 42

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 43

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 44

Complexes containing metals with d¹⁰ electron configurations are typically 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 45

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 46

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 47

Based on the crystal-field strengths Cl^- < F^- < H₂O < NH₃ < H₂NC₂H₄NH₂, which octahedral Ti (III)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 48

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 49

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 50

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 51

Based on electron configuration, which is most likely colorless?

A)[Cu(NH₃)₄]²⁺
B)[Cd(NH₃)₄]²⁺
C)[Ni(NH₃)₆]²⁺
D)[Cr(NH₃)₅Cl]²⁺
E)[Co(NH₃)₆]²⁺

Question 52

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 53

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

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

Question 54

Complexes containing metals with d¹⁰ electron configurations are typically ________.

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

Question 55

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 56

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 57

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)Cl^-
B)NH₃
C)H₂O
D)F^-
E)CN^-

Question 58

Which one of the following ions cannot form both a high spin and a low spin octahedral complex ion?

A)Fe³⁺
B)Co²⁺
C)Cr³⁺
D)Mn³⁺
E)Cr²⁺

Question 59

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

A)d²
B)d¹
C)d⁵
D)d⁸
E)d¹⁰

Question 60

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 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

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

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

Question 63

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

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

Question 64

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

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

Question 65

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

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

Question 66

During the formation of a coordination compound, ligands act as ________.

A)Lewis bases
B)Arrhenius bases
C)Br∅nsted bases
D)Lewis acids
E)Arrhenius acids

Question 67

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 68

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 69

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 70

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

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

Question 71

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 72

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 73

The coordination number of platinum in complexes is always ________.

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

Question 74

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

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

Question 75

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 76

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

A)Lewis acid
B)Br∅nsted acid
C)Arrhenius acid
D)Br∅nsted base
E)Lewis base

Question 77

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

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

Question 78

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

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

Question 79

What is the ligand in Ca₃[Fe(CN)₆]₂?

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

Question 80

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

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