🎉 Announcing Numerade's $26M Series A, led by IDG Capital!Read how Numerade will revolutionize STEM Learning

Chapter 22

Transition Metals and Coordination Compounds

Educators

+ 3 more educators

Problem 1

When a transition metal atom forms an ion, which electrons are lost first?

Rikhil M.
Numerade Educator

Problem 2

Explain why transition metals exhibit multiple oxidation states instead of a single oxidation state (which most of the main-group metals do).

Md M.
Auburn University Main Campus

Problem 3

Why is the +2 oxidation state so common for transition metals?

Rikhil M.
Numerade Educator

Problem 4

Explain why atomic radii of elements in the third row of the transition metals are no larger than those of elements in the second row.

Md M.
Auburn University Main Campus

Problem 5

Gold is the most electronegative transition metal. Explain.

Rikhil M.
Numerade Educator

Problem 6

Briefly define each term.
a. coordination number
b. ligand
c. bidentate and polydentate
d. complex ion
e. chelating agen

Md M.
Auburn University Main Campus

Problem 7

Using the Lewis acid-base definition, how would you categorize a ligand? How would you categorize a transition metal ion?

Rikhil M.
Numerade Educator

Problem 8

Explain the differences between each pair of isomer types.
a. structural isomer and stereoisomer
b. linkage isomer and coordination isomer
c. geometric isomer and optical isomer

Md M.
Auburn University Main Campus

Problem 9

Which complex ion geometry has the potential to exhibit cis-trans isomerism: linear, tetrahedral, square planar, octahedral?

Rikhil M.
Numerade Educator

Problem 10

How can you tell whether a complex ion is optically active?

Md M.
Auburn University Main Campus

Problem 11

Explain the differences between weak-field and strong-field metal complexes.

Rikhil M.
Numerade Educator

Problem 12

Explain why compounds of Sc3+ are colorless, but compounds of Ti3+ are colored.

Md M.
Auburn University Main Campus

Problem 13

Explain why compounds of Zn2+ are white, but compounds of Cu2+ are often blue or green.

Rikhil M.
Numerade Educator

Problem 14

Explain the differences between high-spin and low-spin metal complexes.

Md M.
Auburn University Main Campus

Problem 15

Why are almost all tetrahedral complexes high-spin?

Rikhil M.
Numerade Educator

Problem 16

Many transition metal compounds are colored. How does crystal field theory account for this?

Md M.
Auburn University Main Campus

Problem 17

Write the ground state electron configuration for each atom and ion pair.
a. Ni, Ni2+
b. Mn, Mn4+
c. Y, Y+
d. Ta, Ta2+

Rikhil M.
Numerade Educator

Problem 18

Write the ground state electron configuration for each atom and ion pair.
a. Zr, Zr2+
b. Co, Co2+
c. Tc, Tc3+
d. Os, Os4

Md M.
Auburn University Main Campus

Problem 19

Determine the highest possible oxidation state for each element.
a. V
b. Re
c. Pd

Rikhil M.
Numerade Educator

Problem 20

Which first-row transition metal(s) has the following highest possible oxidation state?
a. +3
b. +7
c. +4

Md M.
Auburn University Main Campus

Problem 21

Determine the oxidation state and coordination number of the metal ion in each complex ion.
a. [Cr(H2O)6]3+
b. [Co(NH3)3Cl3]-
c. [Cu(CN)4]2-
d. [Ag(NH3)2]+

David C.
Numerade Educator

Problem 22

Determine the oxidation state and coordination number of the metal ion in each complex ion.
a. [Co(NH3)5Br]2+
b. [Fe(CN)6]4-
c. [Co(ox)3]4-
d. [PdCl4]2-

Md M.
Auburn University Main Campus

Problem 23

Name each complex ion or coordination compound.
a. [Cr(H2O)6]3+
b. [Cu(CN)4]2-
c. [Fe(NH3)5Br]SO4
d. [Co(H2O)4(NH3)(OH)]Cl2

Rikhil M.
Numerade Educator

Problem 24

Name each complex ion or coordination compound.
a. [Cu(en)2]2+
b. [Mn(CO)3(NO2)3]2+
c. Na[Cr(H2O)2(ox)2]
d. [Co(en)3][Fe(CN)6]

Md M.
Auburn University Main Campus

Problem 25

Write the formula for each complex ion or coordination compound.
a. hexaamminechromium(III)
b. potassium hexacyanoferrate(III)
c. ethylenediaminedithiocyanatocopper(II)
d. tetraaquaplatinum(II) hexachloroplatinate(IV)

Mercedes M.
Numerade Educator

Problem 26

Write the formula for each complex ion or coordination compound.
a. hexaaquanickel(II) chloride
b. pentacarbonylchloromanganese(I)
c. ammonium diaquatetrabromovanadate(III)
d. tris(ethylenediamine)cobalt(III) trioxalatoferrate(III)

Md M.
Auburn University Main Campus

Problem 27

Write the formula and the name of each complex ion.
a. a complex ion with Co3+ as the central ion and three NH3 molecules and three CN- ions as ligands
b. a complex ion with Cr3+ as the central ion and a coordination number of 6 with ethylenediamine ligands

Rikhil M.
Numerade Educator

Problem 28

Write the formula and the name of each complex ion or coordination compound.
a. a complex ion with four water molecules and two ONO- ions connected to an iron(III) ion
b. a coordination compound made of two complex ions: one a complex of vanadium(III) with two ethylenediamine molecules and two Cl- ions as ligands and the other a complex of nickel(II) having a coordination number of 4 with Cl- ions as ligands

Md M.
Auburn University Main Campus

Problem 29

Draw two linkage isomers of [Mn(NH3)5(NO2)]2+.

James I.
Numerade Educator

Problem 30

Draw two linkage isomers of [PtCl3(SCN)]2-.

Md M.
Auburn University Main Campus

Problem 31

Write the formulas and names for the coordination isomers of [Fe(H2O)6]Cl2.

Rikhil M.
Numerade Educator

Problem 32

Write the formulas and names for the coordination isomers of [Co(en)3][Cr(ox)3].

Md M.
Auburn University Main Campus

Problem 33

Which complexes exhibit geometric isomerism?
a. $\left[\mathrm{Cr}\left(\mathrm{NH}_{3}\right)_{5}(\mathrm{OH})\right]^{2+}$
b. $\left[\mathrm{Cr}(\mathrm{en})_{2} \mathrm{Cl}_{2}\right]^{+}$
c. $\left[\mathrm{Cr}\left(\mathrm{H}_{2} \mathrm{O}\right)\left(\mathrm{NH}_{3}\right)_{3} \mathrm{Cl}_{2}\right]^{+}$
d. $\left[\mathrm{Pt}\left(\mathrm{NH}_{3}\right) \mathrm{Cl}_{3}\right]^{-}$
e. $\left[\mathrm{Ni}(\mathrm{CO})_{2} \mathrm{Cl}_{2}\right]$

Rikhil M.
Numerade Educator

Problem 34

Which complexes exhibit geometric isomerism?
a. [Co(H2O)2(ox)2]-
b. [Co(en)3]3+
c. [Co(H2O)2(NH3)2(ox)]+
d. [Ni(NH3)2(en)]2+
e. [Ni(CO)2Cl2]

Md M.
Auburn University Main Campus

Problem 35

If W, X, Y, and Z are different monodentate ligands, how many geometric isomers are there for each ion?
a. square planar [NiWXYZ]2+
b. tetrahedral [ZnWXYZ]2+

Rikhil M.
Numerade Educator

Problem 36

How many geometric isomers are there for each species?
a. [Fe(CO)3Cl3]
b. [Mn(CO)2Cl2Br2]+

Md M.
Auburn University Main Campus

Problem 37

Draw the structures and label the type for all the isomers of each ion.
a. [Cr(CO)3(NH3)3]3+
b. [Pd(CO)2(H2O)Cl]+

Ronald P.
Numerade Educator

Problem 38

Draw the structures and label the type for all the isomers of each species.
a. [Fe(CO)4Cl2]+
b. [Pt(en)Cl2]

Md M.
Auburn University Main Campus

Problem 39

Determine if either isomer of [Cr(NH3)2(ox)2]- is optically active.

Rikhil M.
Numerade Educator

Problem 40

Determine if either isomer of [Fe(CO)3Cl3] is optically active.

Md M.
Auburn University Main Campus

Problem 41

Draw the octahedral crystal field splitting diagram for each metal ion.
a. Zn2+
b. Fe3+ (high- and low-spin)
c. V3+
d. Co2+ (high-spin)

Rikhil M.
Numerade Educator

Problem 42

Draw the octahedral crystal field splitting diagram for each metal ion.
a. Cr3+
b. Cu2+
c. Mn3+ (high- and low-spin)
d. Fe2+ (low-spin)

Md M.
Auburn University Main Campus

Problem 43

The [CrCl6]3- ion has a maximum absorbance in its absorption spectrum at 735 nm. Calculate the crystal field splitting energy (in kJ>mol) for this ion.

Rikhil M.
Numerade Educator

Problem 44

The absorption spectrum of the complex ion [Rh(NH3)6]3+ has maximum absorbance at 295 nm. Calculate the crystal field splitting energy (in kJ>mol) for this ion.

Md M.
Auburn University Main Campus

Problem 45

Three complex ions of cobalt(III), [Co(CN)6]3-, [Co(NH3)6]3+, and [CoF6]3-, absorb light at wavelengths of (in no particular order) 290 nm, 440 nm, and 770 nm. Match each complex ion to the appropriate wavelength absorbed. What color would you expect each solution to be?

Rikhil M.
Numerade Educator

Problem 46

Three bottles of aqueous solutions are discovered in an abandoned lab. The solutions are green, yellow, and purple. It is known that three complex ions of chromium(III) were commonly used in that lab: [Cr(H2O)6]3+, [Cr(NH3)6]3+, and [Cr(H2O)4Cl2]+. Determine the likely identity of each of the colored solutions.

Md M.
Auburn University Main Campus

Problem 47

The [Mn(NH3)6]2+ ion is paramagnetic with five unpaired electrons. The NH3 ligand is usually a strong-field ligand. Is NH3 acting as a strong-field in this case?

Rikhil M.
Numerade Educator

Problem 48

The complex [Fe(H2O)6]2+ is paramagnetic. Is the H2O ligand inducing a strong or weak field?

Md M.
Auburn University Main Campus

Problem 49

How many unpaired electrons do you expect each complex ion to have?
a. [RhCl6]3-
b. [Co(OH)6]4-
c. cis-[Fe(en)2(NO2)2]+

Rikhil M.
Numerade Educator

Problem 50

How many unpaired electrons do you expect each complex ion to have?
a. [Cr(CN)6]4-
b. [MnF6]4-
c. [Ru(en)3]2+

David C.
Numerade Educator

Problem 51

How many unpaired electrons do you expect the complex ion [CoCl4]2- to have if it is a tetrahedral shape?

Rikhil M.
Numerade Educator

Problem 52

The complex ion [PdCl4]2- is known to be diamagnetic. Use this information to determine if it is a tetrahedral or square planar structure.

Md M.
Auburn University Main Campus

Problem 53

What structural feature do hemoglobin, cytochrome c, and chlorophyll have in common?

Rikhil M.
Numerade Educator

Problem 54

Identify the central metal atom in each complex.
a. hemoglobin
b. carbonic anhydrase
c. chlorophyll
d. iron blue

Md M.
Auburn University Main Campus

Problem 55

Hemoglobin exists in two predominant forms in our bodies. One form, known as oxyhemoglobin, has O2 bound to the iron and the other, known as deoxyhemoglobin, has a water molecule bound instead. Oxyhemoglobin is a low-spin complex that gives arterial blood its red color, and deoxyhemoglobin is a high-spin complex that gives venous blood its darker color. Explain these observations in terms of crystal field splitting. Would you categorize O2 as a strong- or weak-field ligand?

Rikhil M.
Numerade Educator

Problem 56

Carbon monoxide and the cyanide ion are both toxic because they bind more strongly than oxygen to the iron in hemoglobin (Hb).

Calculate the equilibrium constant value for this reaction.

Does the equilibrium favor reactants or products?

Md M.
Auburn University Main Campus

Problem 57

Recall from Chapter 3 that Cr and Cu are exceptions to the normal orbital filling, resulting in a [Ar]4s13dx configuration. Write the ground state electron configuration for each species.
a. Cr, Cr+, Cr2+, Cr3+
b. Cu, Cu+, Cu2

Rikhil M.
Numerade Educator

Problem 58

Most of the second-row transition metals do not follow the normal orbital filling pattern. Five of them-Nb, Mo, Ru, Rh, and Ag-have a [Kr]5s14dx configuration and Pd has a [Kr] 4d10 configuration. Write the ground state electron configuration for each species.
a. Mo, Mo+, Ag, Ag+
b. Ru, Ru3+
c. Rh, Rh2+
d. Pd, Pd+, Pd2+

Md M.
Auburn University Main Campus

Problem 59

Draw the Lewis diagrams for each ligand. Indicate the lone pair(s) that may be donated to the metal. Indicate any you expect to be bidentate or polydentate.
a. NH3 b. SCN- c. H2O

Rikhil M.
Numerade Educator

Problem 60

Draw the Lewis diagrams for each ligand. Indicate the lone pair(s) that may be donated to the metal. Indicate any you expect to be bidentate or polydentate.
a. CN
b. bipyridyl (bipy), which has the following structure:
c. NO2-

Md M.
Auburn University Main Campus

Problem 61

List all the different formulas for an octahedral complex made from a metal (M) and three different ligands (A, B, and C). Describe any isomers for each complex.

Rikhil M.
Numerade Educator

Problem 62

Amino acids, such as glycine (gly), form complexes with the trace metal ions found in the bloodstream. Glycine, whose structure is shown here, acts as a bidentate ligand coordinating with the nitrogen atom and one of the oxygen atoms.

Draw all the possible isomers of:
a. square planar [Ni(gly)2]
b. tetrahedral [Zn(gly)2]
c. octahedral [Fe(gly)3]

Md M.
Auburn University Main Campus

Problem 63

Oxalic acid solutions remove rust stains. Draw a complex ion that is likely responsible for this effect. Does it have any isomers?

Rikhil M.
Numerade Educator

Problem 64

W, X, Y, and Z are different monodentate ligands.
a. Is the square planar [NiWXYZ]2+ optically active?
b. Is the tetrahedral [ZnWXYZ]2+ optically active

Md M.
Auburn University Main Campus

Problem 65

Hexacyanomanganate(III) ion is a low-spin complex. Draw the crystal field splitting diagram with electrons filled in appropriately. Is this complex paramagnetic or diamagnetic?

KS
Kimberly S.
Numerade Educator

Problem 66

Determine the color and approximate wavelength absorbed most strongly by each solution.
a. blue solution
b. red solution
c. yellow solution

Md M.
Auburn University Main Campus

Problem 67

Draw the structures of all the geometric isomers of [Ru(H2O)2 (NH3)2Cl2]+. Draw the mirror images of any that are chiral.

Rikhil M.
Numerade Educator

Problem 68

A 0.32 mol amount of NH3 is dissolved in 0.47 L of a 0.38 M silver nitrate solution. Calculate the equilibrium concentrations of all species in the solution.

Md M.
Auburn University Main Campus

Problem 69

When a solution of PtCl2 reacts with the ligand trimethylphosphine, P(CH3)3, two compounds are produced. The compounds share the same elemental analysis: 46.7% Pt; 17.0% Cl; 14.8% P; 17.2% C; 4.34% H. Determine the formula, draw the structure, and give the systematic name for each compound.

Rikhil M.
Numerade Educator

Problem 70

Draw a crystal field splitting diagram for a trigonal planar complex ion. Assume the plane of the molecule is perpendicular to the z axis.

Md M.
Auburn University Main Campus

Problem 71

Draw a crystal field splitting diagram for a trigonal bipyramidal complex ion. Assume the axial positions are on the z axis.

Rikhil M.
Numerade Educator

Problem 72

Explain why [Ni(NH3)4]2+ is paramagnetic, while [Ni(CN)4]2- is diamagnetic.

Md M.
Auburn University Main Campus

Problem 73

Sulfide (S2-) salts are notoriously insoluble in aqueous solution.
a. Calculate the molar solubility of nickel(II) sulfide in water. Ksp(NiS) = 3 * 10-16
b. Nickel(II) ions form a complex ion in the presence of ammonia with a formation constant (Kf) of 2.0 * 108: Ni2+ + 6 NH3[Ni(NH3)6]2+. Calculate the molar solubility of NiS in 3.0 M NH3.
c. Explain any differences between the answers to parts a and b.

Check back soon!

Problem 74

Calculate the solubility of Zn(OH)2(s) in 2.0 M NaOH solution. (Hint: You must take into account the formation of Zn(OH)4 2-, which has a Kf = 2 * 1015.)

Md M.
Auburn University Main Campus

Problem 75

Halide complexes of metal M of the form [MX6]3- are found to be stable in aqueous solution. But it is possible that they undergo rapid ligand exchange with water (or other ligands) that is not detectable because the complexes are less stable. This property is referred to as their lability. Suggest an experiment to measure the lability of these complexes that does not employ radioactive labels.

Arun B.
Numerade Educator

Problem 76

The Kf for [Cu(en)2]2+ is much larger than the one for [Cu(NH3)4]2+. This difference is primarily an entropy effect. Explain why and calculate the difference between the S values at 298 K for the complete dissociation of the two complex ions. (Hint: The value of H is about the same for both systems.)

Md M.
Auburn University Main Campus

Problem 77

When solid Cd(OH)2 is added to a solution of 0.10 M NaI, some of it dissolves. Calculate the pH of the solution at equilibrium.

Check back soon!

Problem 78

Two ligands, A and B, both form complexes with a particular metal ion. When the metal ion complexes with ligand A, the solution is green. When the metal ion complexes with ligand B, the solution is violet. Which of the two ligands results in the larger ?

Md M.
Auburn University Main Campus

Problem 79

Which element has the higher first ionization energy, Cu or Au?

Rikhil M.
Numerade Educator

Problem 80

The complexes of Fe3+ have magnetic properties that depend on whether the ligands are strong or weak field. Explain why this observation supports the idea that electrons are lost from the 4s orbital before the 3d orbitals in the transition metals.

Md M.
Auburn University Main Campus

Problem 81

Have each group member choose a row of the transition metals in the periodic table and ask each to look up and graph (where appropriate) a trend, choosing from the following: electron configuration, atomic size, ionization energy, or electronegativity. Present your graph to the group. Describe the general trend and any notable exceptions. If possible, form new groups with individuals who researched the same property for a different row of the periodic table.

Rikhil M.
Numerade Educator

Problem 82

Have each group member write down the names and formulas for two coordination compounds. Taking turns, show the formula to the group, and have the rest of the group members name the compound, with each member contributing one step in the process. Once each group member has had his or her formula named, repeat the process by showing only names to the group and having group members determine the correct formula.

Check back soon!

Problem 83

Working individually, draw a pair of coordination compounds that are isomers. Take turns showing your drawings to the group and having them identify the type of isomerism and the reasons that your drawing demonstrates that type of isomerism. If your group misidentifies your type of isomerism, rather than telling them the correct answer right away, point out the part of the structure that prevents it from being the type of isomerism they identified.

Rikhil M.
Numerade Educator

Problem 84

Divide the electron configurations d1 through d10 among the group members such that every configuration is assigned to at least two group members. Working individually, draw the orbital diagram for the configurations assigned to you, including both high-spin and low-spin diagrams where possible. Present your diagrams to your group. Combine all diagrams into one set for the group.

Check back soon!

Problem 85

Working individually, review one of the applications of coordination complexes. Without you or your group members referring to the text, describe the application you reviewed without mentioning the key words in the heading of the subsection. As each group member describes the application they reviewed, take turns attempting to identify the key words from the heading of the subsection they are describing.

Rikhil M.
Numerade Educator

Problem 86

Many aqueous solutions of complex ions display brilliant colors that depend on the identities of the metal ion and ligand(s). Some ligands bind selectively to certain metal ions and produce a complex ion with characteristic colors. These distinctive complex ions serve as qualitative indicators of the presence of particular metal ions. For example, Fe3+ is identified by the rapid formation of the intensely colored pentaaquathiocyanatoiron(III) complex ion, [Fe(H2O)5SCN]2+, when thiocyanate, SCN-, is added to a
solution containing hexaaquairon(III), [Fe(H2O)6]3+, according to the balanced chemical equation shown here:

Examine the absorption spectrum of an aqueous solution of [Fe(H2O)5SCN]2+ shown here and answer the questions.

a. Based on the spectrum, what is the color of an [Fe(H2O)5SCN]2+ solution?
b. Calculate the crystal field splitting energy, , of [Fe(H2O)5SCN]2+ in kJ>mol.
c. The hexaaquairon(III) complex ion, [Fe(H2O)6]3+, produces a pale violet aqueous solution. Is the crystal field splitting energy, , of [Fe(H2O)6]3+ smaller or larger than the  of [Fe(H2O)5SCN]2+?
d. On the basis of your answers to parts b and c, compare the crystal field strengths of water and thiocyanate ligands.
e. The complex ion hexacyanoferrate(III), [Fe(CN)6]3-, is red in aqueous solution. What can you conclude about the relative crystal field splitting energies of [Fe(CN)6]3- and [Fe(H2O)5SCN]2+?

Md M.
Auburn University Main Campus