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Chemistry: The Central Science, 13e (Brown et al.)
Chapter 23 Transition Metals and Coordination Chemistry
23.1 Multiple-Choice Questions
1) Chalcocite, chalcopyrite, and malachite are sources of which metal?
A) manganese
B) copper
C) titanium
D) iron
E) zinc
2) Which mineral contains titanium?
A) pyrolusite
B) chalcopyrite
C) galena
D) rutile
E) sphalerite
3) 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
4) 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
5) 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
6) 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
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.
8) Which one of the following species is paramagnetic?
A) Cu+
B) Cr3+
C) Zn
D) Ca
E) Ag+
9) 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
10) 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
11) What is the most common geometry found in four-coordinate complexes?
A) square planar
B) octahedral
C) tetrahedral
D) icosahedral
E) trigonal bipyramidal
12) 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
13) The coordination number of cobalt in CoCl3 ∙ 6NH3 is ________.
A) 2
B) 3
C) 4
D) 6
E) 8
14) What is the oxidation number of Ni in [Ni(CN)5]3-?
A) 1+
B) 2+
C) 3+
D) 4+
E) 5+
15) 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
16) 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
17) 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
18) 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.
19) How many ligands are there in the coordination sphere of [Co(en)2Cl2]+?
A) 3
B) 6
C) 4
D) 1
E) 0
20) What is the charge on the complex ion in Ca2[Fe(CN)6]?
A) 3-
B) 2+
C) 2-
D) 1-
E) 4-
21) A ligand with a single donor atom is called ________.
A) a chelon
B) a chelate
C) polydentate
D) monodentate
E) bidentate
22) Which of the following is not a chelating agent?
A) chloride anion
B) EDTA
C) porphine
D) ethylenediamine
E) oxalate anion
23) 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
24) In humans, what percent of absorbed iron is found in blood?
A) 15
B) 25
C) 40
D) 60
E) 75
25) 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
26) What are the donor atoms in a porphine molecule?
A) N
B) O
C) S
D) Br
E) F
27) What metal is complexed in chlorophyll?
A) iron
B) chromium
C) manganese
D) vanadium
E) magnesium
28) What form of hemoglobin is purplish-red?
A) myoglobin
B) deoxyhemoglobin
C) heme
D) oxyhemoglobin
E) none of the above
29) How many bonds can ethylenediamine form to a metal ion?
A) 1
B) 2
C) 3
D) 4
E) 6
30) 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+ + C20H10N42- ⇔ Fe(NH3)2(C20H10N4) + 4NH3
E) Cu(NH3)42+ + 6H2O ⇔ Cu(H2O)62+ + 4NH3
31) The chelate effect is best attributed to considerations of which type?
A) hydration
B) enthalpy
C) entropy
D) hydrogen bonding
E) resonance
32) Which one of the following species is a potential polydentate ligand (chelating agent)?
A) NH3
B) Cl-
C) CN-
D) H2O
E) C2O42-
33) 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
34) Which of the following is a polydentate ligand?
A) ammonia
B) oxalate ion
C) chloride ion
D) water
E) hydroxide ion
35) 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
36) 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]
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.
38) Linkage isomerism would most likely occur when which of the following ligands is present?
A) H2O
B) NH3
C) Cl-
D) PF3
E) NCS-
39) 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
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+
41) 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]
42) 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.
43) 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
44) 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
45) 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+
13
46) A complex that absorbs light at 700 nm will appear ________.
A) red
B) green
C) yellow
D) orange
E) violet
47) 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
48) 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-
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+
50) 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
51) Complexes containing metals with d10 electron configurations are typically ________.
A) violet
B) blue
C) green
D) yellow
E) colorless
52) Complexes containing metals with which one of the following electron configurations are usually
colorless?
A) d2
B) d1
C) d5
D) d8
E) d10
53) 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-
54) 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+
55) 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
56) 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
57) 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-
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+
59) 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
17
60) 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.
61) 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.
62) How many d electrons are associated with the metal ion in [Cr(NH3)3+?
A) 1
B) 2
C) 3
D) 4
E) 5
23.2 Bimodal Questions
1) 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
2) The coordination number of platinum in complexes is always ________.
A) 4
B) 5
C) 2
D) 3
E) 6
3) 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
4) 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
5) 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
6) 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
7) How many d electrons are in the cobalt ion of K3[Co(CN)6]?
A) 3
B) 5
C) 6
D) 7
E) 4
8) What is the charge on the complex ion in Mg2[FeCl6]?
A) 2-
B) 2+
C) 3-
D) 3+
E) 4-
9) What is the oxidation number of chromium in Cr[(NH3)4Cl2]Cl?
A) -3
B) +3
C) +2
D) -2
E) 0
10) What is the ligand in Ca3[Fe(CN)6]2?
