Answer at the bottom of the page
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) 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) Diamagmetic 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]BrH2O has which set of ligands in its inner coordination sphere?
A) 3 NH3
B) 3 NH3 and 2Br-
C) 3 NH3 and 1Br-
D) 3 NH3, 1Br-, and 1H2O
E) 3 NH3, 2Br-, and 1H2O
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+
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(H3O)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
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)6]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?
A) Ca2+
B) Fe3+
C) CN-
D) Fe(CN)63-
E) Fe2+
11) 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+
12) What is the oxidation number of cobalt in [Co(NH3)4F2]?
A) -3
B) +2
C) +1
D) +3
E) +6
13) The charge of the complex ion in [Zn(H2O)3Cl]Cl is __________.
A) 0
B) 1-
C) 2+
D) 1+
E) 2-
14) The coordination number for [Zn(H2O)3Cl]Cl is __________.
A) 5
B) 4
C) 2
D) 1
E) 6
15) What is the oxidation state of iron in CaNa[Fe(CN)6]?
A) 0
B) +2
C) +3
D) +4
E) +6
16) What is the oxidation state of iron in K3[Fe(CN)6]?
A) 0
B) +2
C) +3
D) +4
E) +6
17) What is the coordination number of iron in CaNa[Fe(CN)6]?
A) 2
B) 8
C) 4
D) 6
E) 12
18) What is the coordination number of cobalt in [Co(NH3)5Cl](NO3)2?
A) 12
B) 8
C) 4
D) 2
E) 6
19) What is the oxidation state of cobalt in [Co(NH3)5Cl](NO3)2?
A) 0
B) 2
C) 3
D) 4
E) 6
20) What is the oxidation state of chromium in [Cr(H2O)4Cl2]+?
A) 0
B) +2
C) +3
D) -2
E) -3
21) What is the coordination number of chromium in [Cr(H2O)4Cl2]+?
A) 8
B) 6
C) 4
D) 2
E) 12
22) The “dentation” of a ligand is defined by __________.
A) how many “dents” or “deceptions” there are in the coordination sphere of a complex species it forms
B) how many electron donor atoms it utilizes to form coordinate bonds to the central metal ion
C) the total number of lone pairs of electrons it possesses
D) how many metal ions it can sequester from solution
E) none of the above
23) EDTA is __________-dantate ligand.
A) mono
B) bi
C) tri
D) tetra
E) hexa
24) What is the metal ion in the porphyrin of heme?
A) iron
B) calcium
C) molybdenum
D) magnesium
E) chlorophyll
25) How many iron atoms are coordinated in a hemoglobin molecule?
A) 1
B) 2
C) 3
D) 4
E) 5
26) The correct name for [Ni(NH3)6](NO3)3 is __________.
A) dinitrohexaamminenickel (II)
B) hexaamminenickel (III) trinitrate
C) dinitrohexaamminenickelate (III)
D) hexaamminenickel (II) nitrate
E) hexaamminenickel (III) nitrate
27) The correct name for [Cu(NH3)4(H2O)2]+2 is __________.
A) diwaterquatraamminecopper (II)
B) tetraamminediaquacopper (II)
C) diaquatetraammoniumcopper (II)
D) tetraamminecopper (II) dihydrate
E) none of the above
28) The correct name for [Al(H2O)2(OH-)4]- is __________.
A) diwaterquatrahydroxyaluminum
B) tetrahydroxydiaquaaluminum (III)
C) diaquatetrahydroxoaluminate
D) aluminum (IV) hydroxide dihydrate
E) none of the above
29) The correct name for [Co(NH3)5Cl]Cl2 is __________.
A) pentaaminechlorocobalt(III) chloride
B) chloropentaammoniacobalt (II) chloride
C) pentaammoniachlorocobalt(II) chloride
D) cobalt(III) pentaamino trichloride
E) none of the above
30) The names of complex anions end in __________.
A) -o
B) -ium
C) -ate
D) -ous
E) -ic
31) The correct name for Na3[CoF6] is __________.
A) trisodium hexakisfluorocobalt(III)
B) trisodium hexakisfluorocobalt(II)
C) trisodium hexakisfluorocobalt(IV)
D) sodium hexafluorocobaltate(III)
E) sodium hexafluorocobaltate(IV)
32) Triphenylphosphine is often given the abbreviated formula PPh3. The correct name for Rh(PPh3)3Cl is __________.
A) chlorotriphenylphosphinerhodium
B) chlorotriphenylphosphinerhodium(I)
C) tris(triphenylphosphine)chlororhodium(I)
D) chlorotris(triphenylphosphine)rhodium(I)
E) chlorotris(triphenylphosphine)rhodate(-I)
33) In __________, the bonds are the same but the spatial arrangement of the atoms is different.
A) structural isomers
B) linkage isomers
C) coordination-sphere isomers
D) stereoisomers
E) resonance structures
34) A geometrical isomer with like groups located on opposite sides of the metal atom is denoted with the prefix __________.
A) cis-
B) trans-
C) bis-
D) tetrakis-
E) d-
35) The complex [Zn(NH3)2Cl2]2+ does not exhibit cis-trans isomerism. The geometry of this complex must be __________.
A) tetrahedral
B) trigonal bipyramidal
C) octahedral
D) square planar
E) either tetrahedral or square planar
36) How many isomers exist for the octahedral complex ion [Co(NH3)4F2]+?
A) 1
B) 2
C) 3
D) 4
E) 5
37) Trans-[Fe(H2O)2Cl4]2- must be __________.
A) tetrahedral
B) octahedral
C) square planar
D) trigonal bipyramidal
E) linear
38) Linkage isomerism can only occur __________.
A) in cis-isomers of octahedral complexes
B) with cobalt complexes
C) with coordination number 6
D) with tetrahedral complexes
E) with ligands that have more than one possible donor atom
39) Metals with __________ electron configurations characteristically form diamagnetic, square planar complexes.
A) d0
B) d9
C) d6
D) d8
E) d10
23.3 Short Answer Questions
1) Draw a diagram of the short-hand ground state electron configuration of zinc.
2) Most transition metal ions contain partially occupied __________ subshells.
3) A substance is __________ if its ions or atoms have one or more unpaired electrons.
4) The two more common oxidation states of chromium are __________ and __________.
5) __________ arises when the unpaired electrons of the atoms or ions in a solid are influenced by the orientations of the electrons of their neighbors.
6) What is the oxidation state of the iron atom in CaNa[Fe(CN)6]?
7) The most common coordination numbers are __________.
8) What is the coordination number of the iron atom in CaNa[Fe(CN)6]?
9) Six-coordinate complexes generally have __________ geometry.
10) The number of “free” chloride ions in an ionic coordination compound can be determined by treating the compound with __________.
11) The secondary valence in metal ion complexes is called the __________.
12) Werner’s theory of primary and secondary valences for transition metal complexes has given us the concepts of __________ and __________.
13) Transition metal ions with empty valence orbitals act as __________.
14) What is the oxidation number of the central metal in [Mo(H2O)5NO3]Cl2
15) Define the chelate effect.
16) The chelate effect is enhanced by polydentate ligand binding because of the change in __________.
17) List three of the ten transition metals required for human life.
18) Myoglobin has __________ heme group(s) that bind(s) __________.
19) In photosynthesis, __________ moles of photons are required to form one mole of __________.
20) In the leaves of plants, visible light is absorbed by a compound known as __________, and is aided by a __________ ion bonded to a porphyrin ring.
21) What is the mechanism used in humans to combat blood bacterial growth via deprivation of iron?
22) A large difference in formation constant (Kf) of a poly- versus monodentate ligand is called __________.
23) A compound that can occupy two coordination sites is a (an) __________.
24) The porphyrin compound that contains Mg(II) is called __________.
25) The transport of iron into bacteria is facilitated by the formation of the complex __________.
26) Name the compound: K2[Cr(H2O)4(CO3)2]
27) Name Na[Ru(H2O)2(C2O4)2].
28) Two compounds have the same formula and contain an SCN- ligand. In one compound the SCN- ligand is bonded to the metal atom via the N atom and in the other it is bonded via the S atom. These two compounds are examples of __________ isomers.
29) Non superimposable isomers are __________ isomers.
30) How can high-spin and low-spin transition metal complexes be distinguished from each other?
23.4 True/False Questions
1) If chloride is a ligand to a transition metal it will not be precipitated by silver nitrate.
2) The chelate effect must always occur with positive enthalpy change.
3) The color of hemoglobin changes from purple to red when water displaces oxygen on the molecule.
4) The heme unit of myoglobin is bound to the protein via a nitrogen-containing ligand.
5) To separate racemic mixtures the isomers must be in a chiral environment.
6) Green and orange are complementary colors.
7) The energy of a metal ligand complex is higher than the energy of the separated components.
23.5 Essay Questions
1) What is the purpose of adding sodium tripolyphosphate to a detergent?
2) What colors of light does chlorophyll-a absorb?
3) How does an elevated body temperature deprive some bacteria in the body of iron?
4) What is a siderophore?
5) What is meant by the prefix tetrakis-, and when is it used?
6) Name the compound, Ca[AlH4]2.
7) Name the compound, [Os(en)3]2[NiCl2Br2]3.
8) Name the compound, Cu(H2O)42+.
9) In what two ways can an object appear blue?
Answer:
View Answer