Ch24_Testbank

Chemistry, 11e (Brown/LeMay/Brusten/Murphy)Chapter 24: Chemistry of Coordination Compounds

24.1 Multiple-Choice and 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

Answer: E Diff: 1 Page Ref: Sec. 24.1

2) The coordination number of platinum in complexes is always __________.

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

Answer: A Diff: 1 Page Ref: Sec. 24.1

3) During the formation of a coordination compound, the metal acts as a __________.

A) Lewis acid B) C) Arrhenius acid D) E) Lewis base



4) During the formation of a coordination compound, ligands act as __________.

A) Lewis bases B) Arrhenius bases C) 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

Answer: C Diff: 1 Page Ref: Sec. 24.1

6) In the following reaction, is acting as a(n) __________.

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

Answer: B Diff: 1 Page Ref: Sec. 24.1


7) How many d electrons are in the cobalt ion of ?

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


8) What is the charge on the complex ion in ?

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


9) What is the oxidation number of chromium in ?

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



10) What is the ligand in ?

A) B) C)

D)

E)


11) What is the charge of the central metal ion in ?

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

Answer: D Diff: 1 Page Ref: Sec. 24.1

12) What is the oxidation number of cobalt in ?

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



13) The charge of the complex ion in is __________.

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


14) The coordination number for is __________.

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


15) What is the oxidation state of iron in ?

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



16) What is the coordination number of iron in ?

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


17) What is the coordination number of cobalt in ?

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


18) What is the oxidation state of chromium in ?

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



19) What is the coordination number of chromium in ?

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


20) 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


21) EDTA is __________-dantate ligand.

A) mono B) bi C) tri D) tetra E) hexa



22) What is the metal ion in the porphyrin of heme?

A) iron B) calcium C) molybdenum D) magnesium E) chlorophyll


23) How many iron atoms are coordinated in a hemoglobin molecule?

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


24) The correct name for is __________.

A) dinitrohexaamminenickel (II) B) hexaamminenickel (III) trinitrate C) dinitrohexaamminenickelate (III) D) hexaamminenickel (II) nitrate E) hexaamminenickel (III) nitrate



25) The names of complex anions end in __________.

A) -o B) -ium C) -ate D) -ous E) -ic


26) The correct name for is __________.

A) trisodium hexakisfluorocobalt(III) B) trisodium hexakisfluorocobalt(II) C) trisodium hexakisfluorocobalt(IV) D) sodium hexafluorocobaltate(III) E) sodium hexafluorocobaltate(IV)


27) Triphenylphosphine is often given the abbreviated formula . The correct name

for is __________.

A) chlorotriphenylphosphinerhodium B) chlorotriphenylphosphinerhodium(I) C) tris(triphenylphosphine)chlororhodium(I) D) chlorotris(triphenylphosphine)rhodium(I) E) chlorotris(triphenylphosphine)rhodate(-I)



28) 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


29) 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-


30) The complex 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



31) How many isomers exist for the octahedral complex ion ?

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


32) Trans must be __________.

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


33) 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



34) Metals with __________ electron configurations characteristically form diamagnetic, square planar complexes.

A) B) C) D) E)


35) What transition metal is responsible for the color of ruby?

A) manganese B) cobalt C) titanium D) gold E) chromium


24.2 Multiple-Choice Questions

1) Formation of a complex species of metal ion with ligands often __________.

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



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

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


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


4) The coordination number of cobalt in is __________.

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



5) What is the oxidation number of Ni in ?

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


6) 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


7) In the compound, , what ligands are in the coordination sphere?

A) B) C)

D) E) none of the above



8) What are the respective central-metal oxidation state, coordination number, and overall charge on the complex ion in

?

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


9) Which one of the following species is paramagnetic?

A) B) C) Zn D) Ca E)


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

A)

B)

C)

D)

E) None of these complexes has coordination number 6.



11) How many ligands are there in the coordination sphere of ?

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


12) What is the charge on the complex ion in ?

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


13) A ligand with a single donor atom is called __________.

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



14) Which of the following is not a chelating agent?

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


15) What is the purpose of adding EDTA to prepared foods?

A) to keep ions such as 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


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

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



17) The coordination number and oxidation number of the central atom in are _________ and _________, respectively.

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


18) What purpose would sodium tripolyphosphate serve in a detergent formulation?

A) to aid in removal of rust stains from surfaces and from clothes B) to aid in keeping the inside of washing machines clean and free from corrosion C) to improve the flow characteristics of the detergent in the box D) to complex and hence sequester metal ions in hard water E) to reduce bacterial growth in the detergent upon storage


19) What are the donor atoms in a porphine molecule?

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



20) What metal is complexed in chlorophyll?

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


21) What form of hemoglobin is purplish-red?

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


22) How many bonds can ethylenediamine form to a metal ion?

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



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

A)

B)

C)

D)

E)


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

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


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

A)

B) C)

D)

E)



26) 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


27) Which of the following is a polydentate ligand?

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


28) A complex of correctly written formula has which set of ligands in its inner coordination sphere?

A)

B) and

C) and

D) , and

E) , and



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

A)

B)

C)

D)

E)


30) Does either or both cis- or trans- have optical isomers?

A) cis only B) trans only C) both cis and trans D) neither cis nor trans E) does not exhibit cis-trans isomerism.


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

A)

B)

C)

D)

E)



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


33) Which of the following will display optical isomerism?

A) square-planar

B) square-planar

C) octahedral

D) octahedral

E) octahedral


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

A)

B)

C)

D)

E)



35) Which one of the following complexes can exhibit geometrical isomerism?

A) (square planar)

B) (tetrahedral)

C) (square planar)

D) (octahedral) E) All of the above can exhibit geometrical isomerism.


36) 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.


37) 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.



38) Based on electron configuration, which is most likely colorless?

A)

B)

C)

D)

E)


39) A complex that absorbs light at 700 nm will appear __________.

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


40) 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



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

A)

B)

C)

D)

E)

Answer: E Diff: 2 Page Ref: Sec. 24.5, 24.6

42) Which one of the following complex ions will be paramagnetic?

A) (low spin)

B) (low spin)

C) (low spin)

D)

E)

Answer: B Diff: 2 Page Ref: Sec. 24.5, 24.6

43) Complexes containing metals with 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.



44) Complexes containing metals with electron configurations are typically __________.

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


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

A) B) C) D) E)


46) Which one of the following is a strong-field ligand?

A)

B)

C) D) E)



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)

C) D) E)


48) Based on the crystal-field strengths which

Co(III) complex is most likely high-spin?

A)

B)

C)

D)

E)


49) 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



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


51) Based on the crystal-field strengths , which octahedral Ti(III) complex below has its d-d electronic transition at shortest wavelength?

A)

B)

C)

D)

E)



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

A) B) C) D) E)


53) 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 large splitting A)

B)

C)

D) E) not enough information given to determine


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

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



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

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

Answer: A Diff: 1 Page Ref: Sec. 24.6 56) How many d electrons are associated with the metal ion in ?

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


24.3 Short Answer Questions

1) What is the oxidation state of the iron atom in ?

Answer: +3 Diff: 2 Page Ref: Sec. 24.1

2) The most common coordination numbers are __________.

Answer: 4 and 6 Diff: 1 Page Ref: Sec. 24.1


3) What is the coordination number of the iron atom in ?

Answer: 6 Diff: 1 Page Ref: Sec. 24.1

4) Six-coordinate complexes generally have __________ geometry.

Answer: octahedral Diff: 1 Page Ref: Sec. 24.1

5) The number of "free" chloride ions in an ionic coordination compound can be determined by treating the compound with __________.

Answer: Diff: 1 Page Ref: Sec. 24.1

6) The secondary valence in metal ion complexes is called the _________.

Answer: coordination number Diff: 1 Page Ref: Sec. 24.1

7) Werner's theory of primary and secondary valences for transition metal complexes has given us the concepts of __________ and __________.

Answer: oxidation state and coordination number Diff: 1 Page Ref: Sec. 24.1


8) Transition metal ions with empty valence orbitals act as __________.

Answer: Lewis acids Diff: 1 Page Ref: Sec. 24.1

9) What is the oxidation number of the central metal in

Answer: +3 Diff: 1 Page Ref: Sec. 24.1

10) Define the chelate effect.

Answer: Chelate effect = an increased stability of complex compounds formed with chelating (polydentate) ligands compared to those formed with monodentate ligands. Diff: 1 Page Ref: Sec. 24.2

11) The chelate effect is enhanced by polydentate ligand binding because of the change in __________.

Answer: entropy Diff: 2 Page Ref: Sec. 24.2

12) List three of the ten transition metals required for human life.

Answer: Any three of: Co, Cu, Cr, Fe, Mn, V, Zn, Ni, Mo, Cd Diff: 1 Page Ref: Sec. 24.2


13) Myoglobin has __________ heme group(s) that bind(s) __________.

Answer: 1; oxygen Diff: 1 Page Ref: Sec. 24.2

14) In photosynthesis, __________ moles of photons are required to form one mole of __________.

Answer: 48; glucose Diff: 2 Page Ref: Sec. 24.2

15) 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.

Answer: chlorophyll; Mg Diff: 2 Page Ref: Sec. 24.2

16) What is the mechanism used in humans to combat blood bacterial growth via deprivation of iron?

Answer: fever Diff: 2 Page Ref: Sec. 24.2

17) A large difference in formation constant of a poly- versus monodentate ligand is called __________.

Answer: chelate effect Diff: 1 Page Ref: Sec. 24.2


18) A compound that can occupy two coordination sites is a (an) __________.

Answer: bidentate ligand Diff: 1 Page Ref: Sec. 24.2

19) The porphyrin compound that contains Mg(II) is called __________.

Answer: chlorophyll Diff: 1 Page Ref: Sec. 24.2

20) The transport of iron into bacteria is facilitated by the formation of the complex __________.

Answer: ferrichrome Diff: 1 Page Ref: Sec. 24.2

21) Name the compound:

Answer: potassium tetraaquadicarbonatochromate(II) Diff: 3 Page Ref: Sec. 24.3

22) Name

Answer: sodium diaquadioxalatoruthenate (III) Diff: 1 Page Ref: Sec. 24.3


23) Two compounds have the same formula and contain an ligand. In one

compound the 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.

Answer: linkage Diff: 1 Page Ref: Sec. 24.4

24) Non superimposable isomers are __________ isomers.

Answer: optical, chiral, enantiomeric Diff: 1 Page Ref: Sec. 24.4

25) How can high-spin and low-spin transition metal complexes be distinguished from each other?

Answer: Magnetic properties and absorption spectra can be compared. Diff: 1 Page Ref: Sec. 24.6

24.4 True/False Questions

1) If chloride is a ligand to a transition metal it will not be precipitated by silver nitrate. Answer: True

Diff: 1 Page Ref: Sec. 24.1

2) The chelate effect must always occur with positive enthalpy change. Answer: False



3) The color of hemoglobin changes from purple to red when water displaces oxygen on the molecule. Answer: False


4) The heme unit of myoglobin is bound to the protein via a nitrogen-containing ligand. Answer: True


5) An enzyme must contain a metal ion to be chiral. Answer: False


6) To separate racemic mixtures the isomers must be in a chiral environment. Answer: True


7) Green and orange are complementary colors. Answer: False


8) Transition metal complexes, whose metal ions have some number of unpaired electrons, are paramagnetic Answer: True Diff: 1 Page Ref: Sec. 24.5


9) The energy of a metal ligand complex is higher than the energy of the separated components. Answer: False


10) Transition metal complexes are colored because of the energy gap between the d orbitals. Answer: True


24.5 Essay Questions.

1) What is the purpose of adding sodium tripolyphosphate to a detergent?

Answer: to sequester the metal ions in hard water to prevent their interference with the action of the detergent Diff: 1 Page Ref: Sec. 24.2

2) What colors of light does chlorophyll-a absorb?

Answer: red and blue Diff: 1 Page Ref: Sec. 24.2

3) How does an elevated body temperature deprive some bacteria in the body of iron?

Answer: in some bacteria, siderophore production decreases as temperature increases Diff: 1 Page Ref: Sec. 24.2


4) What is a siderophore?

Answer: a ligand that forms an extremely stable water-soluble complex, such as ferrichrome, with iron Diff: 1 Page Ref: Sec. 24.2

5) What is meant by the prefix tetrakis-, and when is it used?

Answer: It means 4 and is used when there are 4 of a ligand whose name includes a Greek prefix. Diff: 1 Page Ref: Sec. 24.3

6) Name the compound,

Answer: calcium tetrahydroaluminate Diff: 1 Page Ref: Sec. 24.3

7) Name the compound,

Answer: tris(ethylenediamine)osmium(III) dibromodichloronickelate(II) Diff: 2 Page Ref: Sec. 24.3

8) Name the compound, .

Answer: tetraaquacopper(II) Diff: 1 Page Ref: Sec. 24.3


9) In what two ways can an object appear blue?

Answer: absorb all wavelengths except blue and reflect or transmit only blue, or absorb the complementary color of blue and reflect or transmit all others Diff: 1 Page Ref: Sec. 24.5

Ch24_Testbank

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