Unit 4 Exam-Styled Questions

B

Which of the following coordination complexes is expected to be the most inert toward ligand substitution?

a. [Ni(Cl)₆]^4-

b. [Ni(CN)₆]^3-

c. [Ni(NH3)₆]²⁺

d. [Ni(CN)₆]^4-

e. [Ni(Br)₆]⁴

D

By replacing the H₂O ligands in the complex shown below with P(CH₃)₃, the ligand exchange kinetics significantly increases in speed. What type of mechanism does this support?

a. Associative

b. Outer sphere electron transfer

c. Alkyl migration

d. Dissociative

e. CO insertion

C

Which complex below would you expect to have the highest thermodynamic stability

based on the chelate effect?

a. [Cu(H₂O)₆]²⁺

b. [Cu(NH₃)₄]²⁺

c. [Cu(en)₃]²⁺

d. [Cu(Cl)₄]^2-

e. [Cu(en)(NH₃)₄]²⁺

C

Which statement best describes the inner sphere mechanism?

a. Electron transfer occurs without any direct interaction between the metal centers.

b. A very fast electron transfer reaction where no ligand is exchanged.

c. Typically requires a ligand to bridge the two metal centers, facilitating electron transfer.

d. Occurs only in square planar complexes.

e. None of the statements are correct.

D

What is the total electron count of the coordination complex shown below and what is the oxidation state of Mo?

a. 16e^- total, Mo²⁺

b. 18e^- total, Mo²⁺

c. 12e^- total, Mo³⁺

d. 18e^- total, Mo¹⁺

e. 16e^- total, Mo¹⁺

E

What is the total electron count of the coordination complex shown below and what is the oxidation state of Pd?

a. 18e^- total, Pd⁰

b. 18e^- total, Pd²⁺

c. 16e^- total, Pd⁰

d. 14e^- total, Pd⁰

e. 16e^- total, Pd²⁺

B

What is the total electron count of the coordination complex shown below and what is the oxidation state of Ni?

a. 14e^- total, Ni⁰

b. 16e^- total, Ni²⁺

c. 16e^- total, Ni⁰

d. 18e^- total, Ni²⁺

e. 18e^- total, Ni³⁺

D

What is the total electron count of the coordination complex shown below and what is the oxidation state of Mo?

a. 16e^- total, Rh²⁺

b. 18e^- total, Rh²⁺

c. 20e^- total, Rh³⁺

d. 18e^- total, Rh³⁺

e. 16e^- total, Rh⁰

C

Which of the coordination complexes below will most likely have a square planar geometry?

a. [ZnCl4]^2-

b. [Hg(CN)4]^2-

c. [Ag(CN)4]^1-

d. [Cd(CN)4]^2-

e. [Ag(CN)6]³

E

Which orbital from the metal Mo center in the complex below will likely overlap with the p_z orbitals in the Cyclopentadienyl ligand?

a. d_yx

b. p_x

c. d_x²-y²

d. p_y

e. d_xz

A

What type of reaction is shown below?

a. Oxidative addition

b. Reductive elimination

c. Metathesis

d. Dissociation

e. Addition

B

What type of reaction occurs in Step 1 and Step 2 as shown below?

a. Dissociation, oxidative addition

b. Reductive elimination, oxidative addition

c. β – elimination, oxidative addition

d. Dissociation, insertion reaction

e. Addition, reductive elimination

C

Which complex below is expected to have the longest C – O bond length?

a. [Mn(CO)₆]⁺

b. Cr(CO)₆

c. [Ti(CO)₆]^2-

d. [Fe(CO)₆]²⁺

e. [V(CO)₆]^-

C

Which statement below correctly describes the trans effect?

a. The trans effect is the preference of strong σ-donor ligands to weaken the bond to the ligand cis to them, increasing its substitution rate.

b. The trans directing ligand strengthens the metal – ligand bond trans to it.

c. The trans effect is the ability of certain ligands, especially strong σ-donors or good π- acceptors, to increase the rate of substitution of the ligand positioned trans to them.

d. The trans effect is the preference of strong π -donor ligands to strengthen the bond to the ligand trans to them, increasing its substitution rate.

e. None of these statements are correct

E

Which complex below is most likely to undergo a metathesis reaction?

a. Ni(H2O)₄

b. Mn(CO)₃Cp

c. Pd(PPh₃)₄

d. Fe(CO)₅

e. TiCl₂Cp₂

E

The variable temperature ¹³C NMR of Ru(C₆H₆)² shows only a single peak at room temperature and at lower temperatures. Which chemical formula best describes the hapticity of this complex based on the NMR spectrum?

a. Ru(η₁-C₆H₆)₂

b. Ru(η₂-C₆H₆)₂

c. Ru(η₃-C₆H₆)₂

d. Ru(η₄-C₆H₆)₂

e. Ru(η₆-C₆H₆)₂

A

Suppose you have [Pt(Cl)₄]^2- as your starting material. What addition of reagents would result in having cis-[Pt(NH₃)(NO₂)₂] as your product?

A. First, add NH₃, then add [NO₂]^-

B. First, add 2NH₃, then add [NO₂]^-

C. First, add [NO₂]^-, then add NH₃

D. First, add [NO₂]^-, then add 2NH₃

E. None of the above

C

Suppose you have [Pt(Cl)₄]^2- as your starting material. What addition of reagents would result in having trans-[Pt(NH₃)(NO₂)₂] as your product?

A. First, add NH₃, then add [NO₂]^-

B. First, add 2NH₃, then add [NO₂]^-

C. First, add [NO₂]^-, then add NH₃

D. First, add [NO₂]^-, then add 2NH₃

E. None of the above

A

What reaction is shown in the picture?

A. reductive elimination

B. 1,1-insertion

C. oxidative addition

D. β-hydrogen elimination

C

What reaction is shown in the picture?

A. reductive elimination

B. 1,1-insertion

C. oxidative addition

D. β-hydrogen elimination

D

What reaction is shown in the picture?

A. reductive elimination

B. 1,1-insertion

C. oxidative addition

D. β-hydrogen elimination

B

How would the rate change of the dissociative substitution reaction with the following scenario: the leaving group on [RhCl(OH₂)₅]²⁺ changes from Cl^- to Br^-?

A. The rate would increase

B. The rate would decrease

C. The rate would be unchanged

D. None of the above

C

How would the rate change of the dissociative substitution reaction with the following scenario: the entering group on [RhCl(OH₂)₅]²⁺ changes from Cl^- to F^-?

A. The rate would increase

B. The rate would decrease

C. The rate would be unchanged

D. None of the above

A

Consider the substitution reaction: [Pd(PMe₃)₄]²⁺ + 2 NH₃) → ?

Select the product of the substitution reaction. Note that the rreaction will not be balanced.

A. cis-[Pd(PMe₃)₂(NH₃)₂]²⁺

B. trans-[Pd(PMe₃)₂(NH₃)₂]²⁺

C. [Pd(PMe₃)₄]²⁺

D. [Pd(NH₃)₄]²⁺

C

What is the electron count for the organometallic complex (η⁵-C₅H₅)₂?

A. 12

B. 14

C. 16

D. 18

E. 20

A

[Co(CN)₅]^3- + [Co(NH₃)₄OH]²⁺ → [Co(CN)₅OH]^3- + [Co(NH₃)₅]²⁺

Determine what type of reaction is occurring in the scheme above.

A. inner-sphere mechanism

B. outer-sphere mechanism

C. metathesis

D. β-hydrogen elimination

B

[Ir₆]^2- + [Fe(CN)₆]^4- → [Ir₆]^3- + [Fe(CN)₆]^3-

Determine what type of reaction is occurring in the scheme above.

A. inner-sphere mechanism

B. outer-sphere mechanism

C. metathesis

D. β-hydrogen elimination

D

What is the dⁿ count for the following complex?

Mo(CO)₅^2-

A. 2

B. 4

C. 6

D. 8

E. 10

E

What is the dⁿ count for the following complex?

Pt(PPh₃)₄

A. 2

B. 4

C. 6

D. 8

E. 10

C

What is the dⁿ count for the following complex?

Mo(CO)₅^2-

A. 2

B. 4

C. 6

D. 8

E. 10