Transition Metals and Coordination ChemistryChapter 19 E-mail: benzene4president@gmail.comWeb-site: http://clas.sa.ucsb.edu/staff/terri/

Transition Metals and Coordination Chemistry – Ch. 191. Which of the following substances can NOT act as a ligand?

a. H2Ob. OH–

c. COd. NH4

+

e. Br–

Transition Metals and Coordination Chemistry – Ch. 192. Which of the following can act as a chelate? Circle all that apply.

a. NH2CH2CH2NH2

b. C2O42–

c. NH2CH2CH2NHCH2CH2NH2

d. SCN–

Transition Metals and Coordination Chemistry – Ch. 19

Transition Metals and Coordination Chemistry – Ch. 193. Fill in the following table:

Name Formula

lithium hexahydroxoferrate(III)

diamminedichloro(ethylendiamine)chromium(III) sulfate

potassium tetrabromodicyanoplatinate(II)

bis(ethylenediamine)oxalatomanganese(IV) nitrate

Transition Metals and Coordination Chemistry – Ch. 194. Fill in the following table:

Substance/Ion Ox # Coord. # Name

[Pt(NH3)3Br]+

K[Co(en)BrCl3]

[Ni(CO)4] Br2

Na[Mn(C2O4)2(CN)2]

[Cu(NH3)4(H2O)2][PtI6]

Transition Metals and Coordination Chemistry – Ch. 195. Which of the following can NOT form linkage isomers?

a. SCN–

b. NO2–

c. NO3–

d. all can form linkage isomers

Transition Metals and Coordination Chemistry – Ch. 196. Rank the following 0.1M aqueous solutions by their conductivity in

water.I. [Cr(H2O)6]Cl3

II. [Cr(H2O)4Cl2]Cl•(H2O)2

III. [Cr(H2O)5Cl]Cl2•H2O

What type of isomers are illustrated above?

Transition Metals and Coordination Chemistry – Ch. 197. Which of the following substances can have geometric isomers?

a. [Co(NH3)5Cl]SO4

b. [Co(NH3)6]Cl3

c. Li[Co(NH3)3Cl3]d. K[Co(NH3)2Cl4]e. Na3[CoCl6]

Transition Metals and Coordination Chemistry – Ch. 198. Give the number of geometric isomers for the octahedral compound

[MA2B2C2], where A, B, and C represent ligands.

a. 1b. 2c. 3d. 5e. 6

Transition Metals and Coordination Chemistry – Ch. 199. For the process Co(NH3)5Cl2+ + Cl– ® Co(NH3)4Cl2

+ + NH3, what would be the ratio of cis to trans isomers in the product?a. 1:1b. 1:2c. 1:4d. 4:1e. 2:1

Transition Metals and Coordination Chemistry – Ch. 19

10. Which of the following statements about 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 geometric isomers,

but no optical isomers.c. The complex ion exhibits two geometric isomers (cis and

trans) and two optical isomers.d. The geometric isomers of the complex ion have identical

chemical properties.

Transition Metals and Coordination Chemistry – Ch. 1911. The compound Co(NH3)4Cl3 (233.44g/mol) has several structural

isomers. A solution is made by dissolving 0.875 g of one of the isomer in 25.0 g of water. The solution freezes at -0.56 °C. (Kf = 1.86 °C kg/mol)

Which of the following is the correct structural isomer?a. [Co(NH3)4Cl3]b. [Co(NH3)4Cl2]Clc. [Co(NH3)4Cl]Cl2

d. [Co(NH3)4]Cl3

Transition Metals and Coordination Chemistry – Ch. 1912. Draw the d orbital diagrams according to the crystal field model in

order to predict how many unpaired electrons are in each of the following:a. [Fe(CN)6]3- b. [CoBr6]4- c. [Mn(en)2]3+ (tetrahedral)

Transition Metals and Coordination Chemistry – Ch. 19

d orbitals for a free metal ion

Ener

gy

Octahedral Splitting

Transition Metals and Coordination Chemistry – Ch. 19

d orbitals for a free metal ion

Ener

gy

TetrahedralSplitting

Transition Metals and Coordination Chemistry – Ch. 1913. An orange complex and a violet complex were both found to have

ferric ion as their central metal; which one absorbs light with a longer wavelength?

Transition Metals and Coordination Chemistry – Ch. 1914. Solutions of [Co(NH3)6]3+ , [Co(NO2)6]3-and [CoF6]3- are colored.

The solutions were red, yellow and blue. Match the solution to the color.

Transition Metals and Coordination Chemistry – Ch. 1915. The complex ion [Zn(H2O)6]2+ is colorless whereas [Ni(H2O)6]2+ is

green, explain.

Transition Metals and Coordination Chemistry – Ch. 1916. A crystal that contains a complex ion is known to absorb 266

kJ/mol. Determine the color of the crystal.

Color λ (nm)

Violet 400

Blue 450

Blue-Green 490

Yellow-Green 570

Yellow 580

Orange 600

Red 650

Transition Metals and Coordination Chemistry – Ch. 191. Define:

a. Lewis acid => electron pair acceptor and Lewis base => electron pair donar

b. Ligand => Lewis basec. Chelate => Ligand that can form more than one coordination

covalent bondd. Coordination number => Number of coordination covalent

bonds per metal atome. Counter ion => Oppositely charged ion necessary to neutralize

another ionf. Isomer => Same chemical formula – different properties

Transition Metals and Coordination Chemistry – Ch. 19

2. Rank the following 1 M solutions of structural isomers by their conductivity in water.

a. [Cr(H2O)6]Cl3 [Cr(H2O)6]3+ + 3Cl– (4 ions)

b. [Cr(H2O)4Cl2]Cl•(H2O)2 [Cr(H2O)4Cl2]+ + Cl– + 2H2O (2 ions)

c. [Cr(H2O)5Cl]Cl2•H2O [Cr(H2O)5Cl]2+ + 2Cl– + H2O (3 ions)

Relative conductivity => a > c > b

Transition Metals and Coordination Chemistry – Ch. 19

Name Formula

lithium hexahydroxoferrate(III) Li3[Fe(OH)6]

diamminedichloroethylendiaminechromium(III) sulfate [Cr(NH3)2Cl2(en)]2SO4

bis(ethylenediamine)oxalatomanganese(IV) nitrate[Mn(en)2(ox)](NO3)2

or[Mn(NH2CH2CH2NH2)2(C2O4)](NO3)2

potassium dibromodicyanoplatinate(II) K2[PtBr2(CN)2]

3.

Transition Metals and Coordination Chemistry – Ch. 194.

Substance/Ion Ox # CN Name

[Pt(NH3)3Br]+ +2 4 triamminebromoplatinum(II) ion

K[CoBrCl3(en)] +3 6 potassium bromotrichloro(ethylenediamine)cobalt(III)

[Ni(CO)4] Br2 +2 4 tetracarbonylnickel(II) bromide

Na2[Mn(C2O4)2(CN)(NO2)] +4 6 sodium cyanonitrobisoxalatomanganate(IV)

[Cu(NH3)4(H2O)2][PtI6] +2, +4 6, 6 tetraamminediaquacopper(II) hexaiodoplatinate(IV)

Transition Metals and Coordination Chemistry – Ch. 195. _____ isomers and _____ isomers are classes of structural isomers.

a. Geometric, opticalb. Coordination, geometricc. Linkage, geometricd. Coordination, linkagee. Geometric, linkage

6. Which of the following complexes shows geometric isomerism?a. [Co(NH3)5Cl]SO4

b. [Co(NH3)6]Cl3

c. Li[Co(NH3)3Cl3]d. K[Co(NH3)2Cl4]e. Na3[CoCl6]

Transition Metals and Coordination Chemistry – Ch. 197. Give the number of geometric isomers for the octahedral compound [MA2B2C2], where A, B, and C represent ligands.

a. 1b. 2c. 3d. 5 e. 6

M

AA

B

B

C

C

M

CA

B

A

C

B

M

BA

B

A

C

C

M

AB

A

B

C

C

M

BC

B

C

A

A

Transition Metals and Coordination Chemistry – Ch. 198. For the process Co(NH3)5Cl2+ + Cl– ® Co(NH3)4Cl2

+ + NH3, what would be the ratio of cis to trans isomers in the product?

a. 1:1b. 1:2c. 1:4d. 4:1e. 2:1

Co

ClN

Cl

N

N

N

Co

ClN

N

N

N

N

Co

ClN

N

N

Cl

NCo

ClN

N

Cl

N

ClCo

ClCl

N

N

N

N

Co

ClN

N

Cl

N

N

Transition Metals and Coordination Chemistry – Ch. 19

9. Which of the following statements about 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 geometric isomers, but no optical isomers.c. The complex ion exhibits two geometric isomers (cis and trans) and two optical isomers.d. Because en is a strong field ligand (large Δ), the complex ion is paramagnetic.e. The geometric isomers of the complex ion have identical chemical properties.

Transition Metals and Coordination Chemistry – Ch. 1910. A solution is made by dissolving 0.875 g of Co(NH3)4Cl3 in 25.0 g

of water. The solution freezes at -0.56 °C. (Kf = 1.86 °C kg/mol)Calculate the number of ions (i) produced when Co(NH3)4Cl3 is dissolved in water.

ΔTf = - kfim-0.56C = -(1.86

Ckg/mol)(i)(0.875g/233.44g/mol)/(0.025kg)i = 2 => [Co(NH3)4Cl2]Cl

Transition Metals and Coordination Chemistry – Ch. 1911. An orange complex and a violet complex were both found to have

ferric ion as their central metal; which one absorbs light with a longer wavelength?

The orange complex absorbs blue light and the violet complex absorbs yellow light – λyellow > λblue – so the violet complex absorbs the longer wavelength

Transition Metals and Coordination Chemistry – Ch. 1912. Draw the d orbital diagrams according to the crystal field model in

order to predict how many unpaired electrons are in each of the following:a. [ Fe(CN)6]4-

b. [CoBr6]3-

c. [Fe(H2O)4]3+ (tetrahedral)

Transition Metals and Coordination Chemistry – Ch. 1913. Solutions of [Co(NH3)6]3+ , [Co(NO2)6]3-and [CoF6]3- are colored.

The solutions were red, yellow and blue. Match the solution to the color.

Color Seen Color Absorbed

Relative Wavelength

Relative Energy

Relative Ligand

StrengthLigand

red green medium medium medium NH3

yellow violet shortest highest strongest NO2-

blue orange longest lowest weakest F-

Transition Metals and Coordination Chemistry – Ch. 1914. The complex ion [Zn(H2O)6]2+ is colorless whereas [Ni(H2O)6]2+ is

green, explain.Zn2+ => [Ar]3d10 => since all of the d orbitals are filled the d electrons if excited would have to absorb an energy outside of the visible spectrum => if the compound doesn’t absorb visible light it will be colorless (with the exception of black which is absorbing all visible colors)