Organometallic Chemistry: A Comprehensive Guide for Master's Students

Question 1

In the catalytic cycle of homogeneous catalysis, which step is crucial for initiating the reaction?

Accepted Answer

Oxidative addition

Answer

Ligand exchange

Answer

Reductive elimination

Answer

Electrophilic attack

Question 2

In heterogeneous catalysis, what type of catalyst is employed?

Accepted Answer

Heterogeneous catalyst

Answer

Homogeneous catalyst

Answer

Transition metal

Answer

Base

Question 3

The reaction CH3Cl + Ni(CO)4 → CH3Ni(CO)3Cl + CO exemplifies which type of catalysis?

Accepted Answer

Homogeneous catalysis

Answer

Heterogeneous catalysis

Answer

Autocatalysis

Answer

Enzymatic catalysis

Question 4

In the Haber process, organometallic compounds serve as:

Accepted Answer

Catalysts for converting nitrogen and hydrogen into ammonia.

Answer

Surfaces for the reaction to occur on.

Answer

Impurity removers from the reactants.

Answer

Temperature regulators for the reaction.

Question 5

Which of the following characteristics is NOT typically associated with organometallic compounds?

Accepted Answer

Existence solely as ionic compounds

Answer

Presence of at least one metal-carbon bond

Answer

High reactivity

Answer

Extensive use as catalysts

Question 6

In which type of catalysis do the catalyst and the reactants share the same physical phase?

Accepted Answer

Homogeneous catalysis

Answer

Heterogeneous catalysis

Answer

Electrocatalysis

Answer

Photocatalysis

Question 7

Describe the fundamental mechanism of oxidative addition in organometallic chemistry.

Accepted Answer

Redox process involving the metal center

Answer

Addition of a nucleophile to a metal complex

Answer

Addition of an electrophile to a metal complex

Answer

Loss of a ligand from a metal complex

Question 8

Which of the following factors does NOT influence the stability of an organometallic compound?

Accepted Answer

The pressure

Answer

The nature of the metal

Answer

The type of ligands present

Answer

The oxidation state of the metal

Question 9

What is the key distinction between homogeneous and heterogeneous catalysis?

Accepted Answer

Homogeneous catalysts are dispersed within the reaction mixture, unlike heterogeneous catalysts.

Answer

Heterogeneous catalysts exhibit higher activity compared to homogeneous catalysts.

Answer

Homogeneous catalysts are easier to separate from the reaction products.

Answer

Homogeneous catalysts exhibit higher selectivity than heterogeneous catalysts.

Question 10

Which of the following is NOT an organometallic species?

Accepted Answer

Ionic liquid

Answer

Metallocene

Answer

Carbonyl

Answer

Alkyl

Question 11

What is a key characteristic of a metallocene compound?

Accepted Answer

Contains a metallocene ion, which consists of two cyclopentadienyl ligands bound to a metal centre.

Answer

Is highly stable

Answer

Is Lewis acidic

Answer

Contains a metal-carbon triple bond

Question 12

What is the catalyst used in the production of polyethylene by the Ziegler-Natta process?

Accepted Answer

TiCl₄/Al(C₂H₅)₃

Answer

Pd/C

Answer

Ni(CO)₄

Answer

Cr(CO)₆/H₂

Question 13

What is a key difference between homogeneous and heterogeneous catalysis?

Accepted Answer

Homogeneous catalysts are in the same phase as the reactants, while heterogeneous catalysts are in a different phase.

Answer

Homogeneous catalysts are always chiral, while heterogeneous catalysts are achiral.

Question 14

Which type of reaction involves an increase in the number of metal-ligand bonds?

Accepted Answer

Oxidative addition

Answer

Transfer of electrons from metal to ligand

Answer

Decrease in the number of metal-ligand bonds

Answer

Transfer of electrons from ligand to metal

Question 15

Which of the following best describes the mechanism of the Heck reaction?

Accepted Answer

Palladium-catalyzed carbon-carbon bond formation

Answer

Rhodium-catalyzed carbon-heteroatom bond formation

Answer

Platinum-catalyzed carbon-nitrogen bond formation

Answer

Nickel-catalyzed carbon-oxygen bond formation

Question 16

Which intermediate plays a crucial role in the catalytic cycle of Ziegler-Natta polymerization?

Accepted Answer

Metal-alkyl complex

Answer

Metal-hydride complex

Answer

Metal-alkyne complex

Answer

Metal-carbene complex

Question 17

In the Monsanto process, carbon monoxide acts as:

Accepted Answer

Both a reactant and a ligand

Answer

Only a ligand

Answer

Only a reactant

Answer

Neither a reactant nor a ligand

Question 18

Which structural feature is characteristic of metallocenes?

Accepted Answer

Sandwich structure

Answer

Linear structure

Answer

Trigonal planar structure

Question 19

What is the predominant application of organometallic compounds in the industrial sector?

Accepted Answer

Catalysis

Answer

Pharmaceuticals

Answer

Pigments

Answer

Agrochemicals

Question 20

Which of the following is the correct formula for ferrocene?

Accepted Answer

Fe(C₅H₅)₂

Answer

Fe(C₄H₄)₂

Answer

[Fe(η⁵-C₅H₅)₂]²⁺

Answer

Fe(C₆H₆)₂

Question 21

In an oxidative addition reaction, the metal complex typically:

Accepted Answer

Increases its oxidation state

Answer

Forms a new carbon-carbon bond

Answer

Decreases its oxidation state

Answer

Loses a ligand

Question 22

The term 'π-complex' refers to an organometallic complex where:

Accepted Answer

The metal-ligand bond involves donation of electrons from the ligand to an empty d-orbital on the metal

Answer

The metal-ligand bond involves donation of electrons from the metal to an empty orbital on the ligand

Question 23

Which of the following is a characteristic feature of a metallocene?

Accepted Answer

Contains two cyclopentadienyl ligands

Answer

Is anionic

Answer

Has a tetrahedral geometry

Answer

Is highly reactive

Question 24

In a carbene complex, the carbon atom of the carbene ligand:

Accepted Answer

Is sp²-hybridized

Answer

Is sp³-hybridized

Answer

Is dsp²-hybridized

Answer

Is sp-hybridized

Question 25

Which of the following is a type of migratory insertion reaction?

Accepted Answer

CO insertion

Answer

Cope rearrangement

Answer

Diels-Alder reaction

Answer

Alkene metathesis

Question 26

The Ziegler-Natta catalyst is used for the polymerization of which type of monomer?

Accepted Answer

α-Olefins

Answer

Alkynes

Answer

Ethers

Answer

Aromatic compounds

Question 27

The development of organometallic chemistry has had a significant impact on which field?

Accepted Answer

Pharmaceutical industry

Answer

Aerospace industry

Answer

Automotive industry