Chapter 21 1 Why do transition metals show a lot of chemical similarities

Chapter 21: Transition Metals and Coordination Chemistry

1. Transition metals display great similarities

A)

within a given period

B)

within a given vertical group

C)

with the semimetals

D)

all of these

E)

A and B only

2. Which of the transition metals is the best conductor of heat and electric current?

A)

copper

B)

silver

C)

gold

D)

tungsten

E)

titanium

3. Why do transition metals show a lot of chemical similarities within a given period?

A)

The valence s and p electrons affect their chemistry more so than the inner d and f

electrons, which do not participate in bonding as easily.

B)

The number of electrons within a given period varies only slightly and is

sometimes identical because these metals have more than one ionic form.

C)

All elements in a given period, including the representative elements, have a lot of

chemical similarities due to the gradual increase in atomic number.

D)

The transition metals always fill their s and p orbitals first before filling their d

orbitals, which affects their chemistry.

E)

None of the above is correct.

4. Which of the following is incorrect concerning the 3d, 4d, and 5d transition series?

A)

There is a significant increase in radius in going from the 3d to the 4d metals, but

the 4d and 5d metals are similar in size.

B)

There is a general decrease in size going from left to right for each of these series

due to the increasing nuclear charge.

C)

The separation of hafnium and zirconium found together in nature is difficult due

to their similarities in chemistry, which is attributed to their virtually identical

sizes.

D)

Cerium through lutetium exhibits what is referred to as the lanthanide contraction.

E)

All of the above are correct.

5. The reducing abilities of the first-row transition metals generally __________ going from

left to right across the period.

A)

decrease

B)

increase

C)

stay the same

D)

none of these

E)

remain at 1.0 V

6. Which metal ion has a d5 electron configuration?

A)

Cr2+

B)

Ag+

C)

Mn2+

D)

Os2+

E)

Co2+

7. Which of the following is a d7 ion?

A)

Co(II)

B)

Cu(II)

C)

Mn(II)

D)

Mn(IV)

E)

At least two of the above (a-d) are d7 ions.

8. What is the maximum oxidation state expected for manganese?

A)

+2

B)

+8

C)

+6

D)

+5

E)

+7

9. What is the electron configuration of the Sc(I) ion?

A)

[Ar] 4s14d1

B)

[Ar] 4s13d1

C)

[Ar] 3s13d1

D)

[Ar] 4s2

E)

[Ar] 3d2

10. What is the electron configuration of the Ni(II) ion?

A)

[Ar] 4s23d6

B)

[Ar] 4s13d7

C)

[Ar] 4s23d8

D)

[Ar] 3d8

E)

none of these

11. What is the electron configuration of the Mn(II) ion?

A)

[Ar] 4s23d5

B)

[Ar] 4s13d5

C)

[Ar] 4s23d3

D)

[Ar] 3d5

E)

none of these

12. The electron configuration of Cr3+ is

A)

[Ar] 4s23d1

B)

[Ar] 4s13d2

C)

[Ar] 3d3

D)

[Ar] 4s23d4

E)

none of these

13. The electron configuration for Cr2+ is

A)

[Ar] 4s23d4

B)

[Ar] 4s13d5

C)

[Ar] 3d4

D)

[Ar] 4s23d2

E)

none of these

14. The electron configuration of Ti2+ is

A)

[Ar] 4s2

B)

[Ar] 4s13d1

C)

[Ar] 3d2

D)

[Ar] 4s23d2

E)

none of these

15. A complex ion is a charged species consisting of a metal ion surrounded by

A)

other transition metals

B)

hydrogen ions

C)

ligands

D)

ligands and counter ions

E)

none of these

16. How many ligands are in this representative drawing of a complex ion?

A)

1

B)

3

C)

6

D)

7

E)

8

17. Which of the following transition metals is most likely to form an oxide?

A)

gold

B)

silver

C)

platinum

D)

palladium

E)

copper

18. The phenomenon called __________ contraction is responsible for the great similarity in

atomic size and chemistry of 4d and 5d elements.

A)

transition

B)

coordination

C)

lanthanide

D)

isomeric

E)

none of these

19. Which of the following is true?

A)

The first ionization energy for Zn is significantly higher than that of Sc.

B)

The first ionization energy for Zn is significantly lower than that of Sc.

C)

The third ionization energy for Zn is significantly higher than that of Sc.

D)

The third ionization energy for Zn is significantly lower than that of Sc.

E)

Two of these are correct.

20. Which of the following transition metals are important to the U.S. economy and defense?

A)

chromium and cobalt

B)

manganese

C)

platinum and palladium

D)

all of these

E)

A and B only

21. Which metal is most widely used in the electrical systems of homes and factories?

A)

copper

B)

silver

C)

gold

D)

tungsten

E)

titanium

22. What transition metal is used in stainless steel?

A)

nickel

B)

titanium

C)

chromium

D)

iridium

E)

niobium

23. What transition metal is used in magnets, catalysts, and drill bits?

A)

nickel

B)

copper

C)

platinum

D)

cobalt

E)

titanium

24. True or false: Transition metals show great similarities both within a given period and

within a given vertical group.

25. The metals with the highest ionization energies are most likely to be found in nature in the

elemental state.

26. Metals usually have higher melting points than nonmetals.

27. Co2+ in water is blue.

28. The expected electron configuration of Cu+ is [Ar] 3s13d9.

29. The election configuration of Mn2+ is [Ar] 4s23d3.

30. What transition metal has the combination of toughness, stretchability, and resilience that

makes it ideal for use in bicycle frames?

A)

titanium

B)

platinum

C)

tungsten

D)

nickel

E)

aluminum

31. This transition metal is used in the production of a hard steel used for rock crushers and

bank vaults, and can be found in nodules on the ocean floor.

A)

iron

B)

manganese

C)

magnesium

D)

cobalt

E)

nickel

32. What heavy metal is the most abundant and most important to our civilization?

A)

iron

B)

gold

C)

magnesium

D)

cobalt

E)

copper

33. An element that is a significant component of both brass and bronze is:

A)

nickel

B)

tin

C)

copper

D)

iron

E)

zinc

34. Which 3d transition metal is mixed with concentrated sulfuric acid to give a powerful

cleaning solution for removing organic materials from analytical glassware?

A)

chromium

B)

iron

C)

cobalt

D)

scandium

E)

manganese

35. Which transition metal is valued for its high electrical conductivity and resistance to

corrosion, and is widely used for plumbing?

A)

iron

B)

manganese

C)

magnesium

D)

cobalt

E)

copper

36. What transition metal is mainly used for galvanizing steel?

A)

iron

B)

zinc

C)

copper

D)

cobalt

E)

nickel

37. How many d electrons are present on the metal ion in the complex ion PtCl62–?

A)

8

B)

6

C)

4

D)

3

E)

2

38. Which of the metal ions in the following complex ions has a d5 electron configuration?

A)

V(H2O)62+

B)

Mo(NH3)63+

C)

Co(CN)4–

D)

Fe(CN)63–

E)

RhCl64–

39. What are the oxidation numbers of each central metal atom in the following coordination

compounds?

K3[Fe(CN)6], [Cr(NH3)4Br2]Br, [Ni(H2O)6]Cl2, Na2[TaF7]

A)

3, 3, 3, 5

B)

3, 3, 2, 7

C)

–3, 3, 2, 5

D)

–3, 1, 2, 5

E)

3, 3, 2, 5

40. The coordination theory was proposed by:

A)

Bailar

B)

Jorgensen

C)

Blomstrand

D)

Werner

E)

none of these

41. Ethylenediamine (en) is a bidentate ligand. What is the coordination number of cobalt in

[Co(en)2Cl2]Cl?

A)

four

B)

five

C)

seven

D)

eight

E)

six

42. Which of the following coordination compounds will form a precipitate when treated with

an aqueous solution of AgNO3?

A)

[Cr(NH3)3Cl3]

B)

[Cr(NH3)6]Cl3

C)

[Cr(NH3)Cl]NO3

D)

Na3[Cr(CN)6]

E)

Na3[CrCl6]

43. When 6.3 moles of [Co(NH3)5Cl]Cl2 is dissolved in water, how many moles of ions are in

solution?

A)

3.3

B)

4.3

C)

2.1

D)

19

E)

57

44. A coordination compound of Cu2+ can be described as Cu(NH3)xSO4 and is known to

contain 29.92% NH3 by mass. The value of x is:

A)

2

B)

3

C)

4

D)

6

E)

none of these

45. The empirical formula of a compound with a mass percent composition of 6.78% H, 31.43%

N, 39.76% Cl, and 22.03% Co is consistent with which of the following complexes?

A)

[Co(NH3)3Cl3]

B)

[Co(NH3)4Cl2]Cl

C)

[Co(NH3)5Cl]Cl2

D)

[Co(NH3)6]Cl3

E)

none of these

Suppose you are studying coordination compounds of Co(II) with the ligand pyridine (py,

C5H5N, molar mass = 79.10). You isolate a crystalline compound, and since the only

available anions are Cl– and NO3–, you hypothesize the empirical formula of the

coordination compound must be Cow(py)x(Cl)y(NO3)z.

46. You discover that the complex decomposes in water. You dissolve 0.1000 g of the complex

in H2O and add excess NaHg(SCN)4, which precipitates Co(II) as CoHg(SCN)4(s). After the

precipitate is washed and dried, its mass is 0.1102 g. How many grams of cobalt are

contained in 0.1000 g of the complex?

A)

0.1102

B)

0.0396

C)

0.0132

D)

0.437

E)

0.0548

47. You analyze for pyridine (Kb is approximately 10–9) by dissolving 0.1000 g of complex in

10 mL of H2O and titrating with a 0.01 M HCl solution. Which of the following indicators

should be used to detect the endpoint? (Assume that the initial concentration of pyridine is

approximately 0.01 M.)

A)

bromophenol blue, pH range of color change = 3.0–4.6

B)

methyl red, pH range of color change = 4.8–6.0

C)

bromothymol blue, pH range of color change = 6.0–7.6

D)

thymol blue, pH range of color change = 8.0 –9.6

E)

alizarin yellow, pH range of color change = 10.1–12.0

48. Addition of AgNO3 to aqueous solutions of the complex results in a cloudy white

precipitate, presumably AgCl. You dissolve 0.1000 g of the complex in H2O and perform a

precipitation titration with 0.0500 M AgNO3 as the titrant. Using an electrode that is

sensitive to [Ag+], you reach the endpoint after 9.00 mL of titrant are added. How many

grams of chloride ion were present in the 0.1000-g sample?

A)

4.50  10–4

B)

5.00  10–3

C)

1.77  10–3

D)

6.38  10–2

E)

1.60  10–2

49. Analysis of the data from a titration indicates that a 0.1190-g sample of the complex

contains 0.0844 g of py. Further analysis shows that 0.1190 g of the complex contains a

0.0157 g of cobalt and 0.0189 g of chloride. What is the empirical formula of the complex?

A)

Co(py)6(Cl)(NO3)

B)

Co(py)4Cl2

C)

Co2(py)5(Cl)2(NO3)2

D)

Co3(py)8(Cl)2(NO3)4

E)

Co(py)4(NO3)2

50. In which of the following complexes does the transition metal have a d8 configuration?

A)

PtCl42–

B)

Cu(H2O)62+

C)

Ni(CO)4

D)

Zn(NH3)42+

E)

Fe(CN)63–

51. What is the correct formula for sodium tetrachlorocuprate(II)?

A)

Na2(CuCl6)

B)

Na4(CuCl4)

C)

Na(CuCl4)

D)

Na2(CuCl4)

E)

Na3(CuCl4)

52. What is the correct IUPAC name for [AuCl4(H2O)2]–?

A)

diaquatetrachloroaurate(0) ion

B)

diaquatetrachloroaurate(III) ion

C)

diaquatetrachloroaurate(I) ion

D)

diaquatetrachlorogold(III) ion

E)

diaquatetrachlorogold(I) ion

53. What is the formula for the hexaaquachromium(II) ion?

A)

[Cr(H2O)6]2+

B)

[Cr2(H2O)6]4+

C)

[Cr(H2O)4]2+

D)

[Cr2(H2O)6]2+

E)

[Cr(H2O)6]4–

54. What is the formula for the pentaamminehydroxocopper(II) ion?

A)

[Cu(NH3)(OH)5]3–

B)

[Cu(NH3)5(OH)5]2+

C)

[Cu(NH3)5(OH)]2+

D)

[Cu(NH3)5(OH)5]3–

E)

[Cu(NH3)5(OH)]+

55. The coordination theory was proposed by Alfred Packer.

56. Consider the following complexes:

I.

Pt(NH3)2Cl2

(square planar)

II.

Rh(en)32+

(en = H2N–CH2–CH2–NH2 and is bidentate)

III.

CoCl42–

(tetrahedral)

Which can exhibit cis-trans isomerism?

A)

I

B)

II

C)

III

D)

I, II

E)

I, II, III

57. Which of the following complexes can exhibit optical isomerism? (en = H2N–CH2–CH2–

NH2 and is bidentate)

A)

cis–Co(NH3)4Cl2

B)

trans–Co(en)2Br2

C)

cis–Co(en)2Cl2

D)

Co(NH3)3Cl3

E)

none of these

58. Because they have the same atoms, bonds, and formulas, geometrical isomers have the same

color.

59. Which of the following complexes shows geometrical isomerism?

A)

[Co(NH3)5Cl]SO4

B)

[Co(NH3)6]Cl3

C)

[Co(NH3)5Cl]Cl2

D)

K[Co(NH3)2Cl4]

E)

none of these

60. What is the sum of all isomers (geometrical and optical) that the complex ion Co(en)2Cl2+

exhibits?

A)

0

B)

1

C)

2

D)

3

E)

4

MSC: Conceptual

61. Which complex ion shape is not capable of showing cis–trans isomerism?

A)

octahedral

B)

square planar

C)

tetrahedral

D)

two of these

E)

none of these

62. Give the number of geometrical isomers for the octahedral compound [MA2B2C2], where A,

B, and C represent ligands.

A)

1

B)

2

C)

3

D)

5

E)

none of these

63. For the process Co(NH3)5Cl2+ + Cl– → Co(NH3)4Cl2+ + NH3 what would be the ratio of cis

to trans isomer in the product?

A)

1 : 1

B)

1 : 2

C)

1 : 4

D)

4 : 1

E)

2 : 1

64. The ____ isomer of the complex Ni(en)2Cl2 exhibits optical isomers, but the _____ isomer

does not.

A)

cis, trans

B)

trans, cis

C)

Both isomers exhibit optical isomers.

D)

Neither isomers exhibit optical isomers.

E)

Depends on the wavelength of plane-polarized light used.

65. How many of the following compounds exhibit geometric isomers?

I.

Pt(NH3)2Cl2 (square planar)

II.

[Co(H2O)2]Cl3

III.

Ni(NH3)4(NO2)2

IV.

K2[CoCl4]

A)

0

B)

1

C)

2

D)

3

E)

4

66. Which of the following ligands might give linkage isomers?

A)

NO2–

B)

SCN–

C)

H2NHC2CH2NH2

D)

A and B

E)

A, B, and C

67. Which of the following are structural isomers?

I.

coordination isomers

II.

linkage isomers

III.

geometrical isomers

IV.

optical isomers

A)

I, III

B)

II, IV

C)

I, III, IV

D)

II, III

E)

I, II

68. Which of the following statements concerning the complex ion Co(en)2Cl2+ is true? (en =

ethylenediamine, NH2CH2CH2NH2)?

A)

The complex ion contains Co(I).

B)

The complex ion exhibits cis and trans geometrical isomers, but no optical

isomers.

C)

The complex ion exhibits two geometrical isomers (cis and trans) and two optical

isomers.

D)

Since en is a strong field ligand (large ), the complex ion is paramagnetic.

E)

The geometric isomers of the complex ion have identical chemical properties.

69. Which of the following is true about coordination complexes?

A)

The metal is a Lewis base and the ligands are Lewis acids.

B)

Only complexes with coordination number six are found in nature.

C)

When the ligands approach a transition metal ion in an octahedral field, the dxz, dyz,

and dxy atomic orbitals are affected the least by the ligands.

D)

None of the above is true.

E)

All of the above are true.

70. Which of the following is paramagnetic?

A)

Zn(H2O)62+

B)

Co(NH3)63+ (strong field)

C)

Cu(CN)32–

D)

Mn(CN)62– (strong field)

E)

none of these

71. The complex ions of Zn2+ are all colorless. The most likely explanation for this is:

A)

Zn2+ is paramagnetic.

B)

Zn2+ exhibits “d orbital” splittings in its complexes such that they absorb all

wavelengths in the visible region.

C)

Since Zn2+ is a d10 ion, it does not absorb visible light even though the “d orbital”

splittings are correct for absorbing visible wavelengths.

D)

Zn2+ is not a transition metal ion.

E)

None of these is correct.

72. Copper(I) complexes would be expected to be colorless.

73. Calculate the total number of unpaired electrons in the following complex ions: Zn(OH2)62+,

Ni(CN)42– (square planar), Co(NH3)63+ (strong field).

A)

0

B)

1

C)

2

D)

3

E)

4

74. The complex FeL62+, where L is a neutral ligand, is known to be diamagnetic. The number

of d electrons in this complex ion is:

A)

4

B)

5

C)

6

D)

7

E)

8

75. The geometry of a coordination compound with a coordination number of 4 is

A)

tetrahedral, in order to minimize repulsions between the ligands

B)

octahedral, since there are two different positions possible for each ligand

C)

square planar, to allow room for the counterion because the ligands take up so

much space

D)

linear, since there are two ligands on each side of the transition metal

E)

tetrahedral or square planar, but too difficult to predict based on the information

given

76. Which of the following statements is true about the octahedral complexes of Ni2+?

A)

Both strong- and weak-field complexes are diamagnetic.

B)

The strong-field complex is diamagnetic and the weak-field complex is

paramagnetic.

C)

The strong-field complex is paramagnetic and the weak-field complex is

diamagnetic.

D)

Both strong- and weak-field complexes are paramagnetic.

E)

There are no octahedral complexes of Ni.

77. CuCl2– (linear)

A)

0

B)

1

C)

2

D)

4

E)

5

78. Ni(NH3) 62+

A)

0

B)

1

C)

2

D)

4

E)

5