Question 1

If the equilibrium constant (Keq) of a reaction is 0.5 then which of the following that must be true?

Accepted Answer

A)  The reaction will have an early transition state. 
B)  Reaction equilibrium will favor the products. 
C)  Gibbs free energy (G) is positive. 
D)  Gibbs free energy (G) is negative. 
A)  The reaction will have an early transition state. 
B)  Reaction equilibrium will favor the products. 
C)  Gibbs free energy (G) is positive. 
D)  Gibbs free energy (G) is negative.

Question 2

The hydrogen atom abstraction step in the free radical chlorine of methane is exothermic. Use the Hammond Postulate to speculate on the extent of bond formation and bond cleavage in the transition state.

Accepted Answer

The exothermic nature of this step means

Question 3

The hydrogen atom abstraction step in the free radical bromination of methane is endothermic. Use the Hammond Postulate to speculate on the extent of bond formation and bond cleavage in the transition state.

Accepted Answer

The endothermic nature of this step mean

Question 4

What reactive intermediate is formed when CHBr3 is treated with hydroxide or when diazomethane is irradiated?

Accepted Answer

A)  carbene 
B)  carbanion 
C)  carbocation 
D)  carbon radical 
A)  carbene 
B)  carbanion 
C)  carbocation 
D)  carbon radical

Question 5

Provide the structure of the transition state in the first propagation step of the free radical chlorination of ethane.

Accepted Answer

The answer of Provide the structure of the transition state...

Question 6

Given an activation energy of 15 kcal/mol, use the Arrhenius equation to estimate how much faster the reaction will occur if the temperature is increased from

Accepted Answer

The reacti

Question 7

Which of the presented mechanisms would be the most energetically favorable and thus the most likely mechanism to actually occur for the following free radical chain reaction?
(bond dissociation energies - H-H = 104 kcal/mol; Cl-Cl = 58 kcal/mol; H-Cl = 103 kcal/mol)
H2 + Cl2  2 HCl

Accepted Answer

A)  H2  H∙ + H∙
H∙ + Cl2 → Cl∙ + HCl
H∙ + Cl∙ → HCl 
B)  Cl2  Cl∙ + Cl∙
Cl∙ + H2 → H∙ + HCl
H∙ + Cl2 → HCl + Cl∙ 
C)  H2  H∙ + H∙
H∙ + Cl2 → Cl∙ + HCl
Cl∙ + H2 → HCl + H∙ 
D)  Cl2   Cl∙ + Cl∙
Cl∙ + H2 → H∙ + HCl
H∙ + Cl∙ → HCl 
A)  H2  H∙ + H∙
H∙ + Cl2 → Cl∙ + HCl
H∙ + Cl∙ → HCl 
B)  Cl2  Cl∙ + Cl∙
Cl∙ + H2 → H∙ + HCl
H∙ + Cl2 → HCl + Cl∙ 
C)  H2  H∙ + H∙
H∙ + Cl2 → Cl∙ + HCl
Cl∙ + H2 → HCl + H∙ 
D)  Cl2   Cl∙ + Cl∙
Cl∙ + H2 → H∙ + HCl
H∙ + Cl∙ → HCl

Question 8

Provide the major organic product that results when 2,2,4-trimethylpentane is subjected to free radical bromination.

Accepted Answer

The answer of Provide the major organic product that results...

Question 9

Chlorination of methane can result in a mixture of chlorinated products. What experimental conditions should be used to favor the production of chloromethane over the other chlorinated products?

Accepted Answer

Make sure the molar ratio of m

Question 10

In the reaction of Cl2 with ethane and UV light, which of the following reactions would be a chain termination event(s)?
I. Cl∙ + CH3-CH3 → CH3-CH2-Cl + H∙
II. Cl∙ + CH3-CH3 → CH3-H2C∙ + HCl
III. Cl∙ + CH3-H2C∙ → CH3-CH2-Cl
IV. Cl2 + CH3-H2C∙ → CH3-CH2-Cl + Cl∙
V. Cl2 + UV light → C l∙ + Cl∙

Accepted Answer

A)  reaction V 
B)  reactions I and IV 
C)  reactions III and IV 
D)  reactions I and II 
E)  reaction III 
A)  reaction V 
B)  reactions I and IV 
C)  reactions III and IV 
D)  reactions I and II 
E)  reaction III

Question 11

If the percentage of the axial onformer (on the product side of the reaction) is 42%, what is the ΔG° (in kJ/mol) for the reaction at 25°C? [R = 8.314 J/K∙ mol]

Accepted Answer

The answer of If the percentage of the axial onformer...

Question 12

Consider the conversion of X to Z through the sole intermediate Y. Given the reaction-energy diagram shown below, which step is the rate-limiting step? Explain your reasoning.

Accepted Answer

The conversion of Y to Z has a

Question 13

In an exothermic reaction, are stronger bonds broken and weaker bonds formed or are weaker bonds broken and stronger bonds formed?

Accepted Answer

In an exothermic rea

Question 14

Which of the following is a propagation step in the free radical chlorination of dichloromethane?

Accepted Answer

A)  ∙ CHCl2 + Cl2 → CHCl3 + Cl∙ 
B)  ∙ CHCl2 + Cl∙ → CHCl3 
C)  CH2Cl2 + Cl∙ → CHCl3 + H∙ 
D)  Cl2 + UV light → 2 Cl∙ 
E)  ∙ CHCl2 + ∙ CHCl2 → CHCl2CHCl2 
A)  ∙ CHCl2 + Cl2 → CHCl3 + Cl∙ 
B)  ∙ CHCl2 + Cl∙ → CHCl3 
C)  CH2Cl2 + Cl∙ → CHCl3 + H∙ 
D)  Cl2 + UV light → 2 Cl∙ 
E)  ∙ CHCl2 + ∙ CHCl2 → CHCl2CHCl2

Question 15

When acetaldehyde (CH3CHO) is deprotonated, the resulting anion is stabilized by resonance. Draw the major resonance contributing forms of this anion.

Accepted Answer

Question 16

How many distinct monochlorinated products can result when isobutane is subjected to free radical chlorination?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  5 
A)  1 
B)  2 
C)  3 
D)  4 
E)  5

Question 17

When light is shined on a mixture of chlorine and chloromethane, carbon tetrachloride is one of the components of the final reaction mixture. Propose a series of mechanistic steps which explain this observation.

Accepted Answer

CH₃Cl + Cl∙ → ∙ CH₂Cl + HCl ∙ CH

Question 18

What is the CCC bond angle in (CH3)3C+?

Accepted Answer

Question 19

Draw the product of the monochlorination of methane with Cl2 in the presence of light or heat.

Accepted Answer

Question 20

The difference in energy between reactants and the transition state is known as ________.

Accepted Answer

the activa

Exam 4: The Study of Chemical Reactions

If the equilibrium constant (Keq) of a reaction is 0.5 then which of the following that must be true?

The hydrogen atom abstraction step in the free radical chlorine of methane is exothermic. Use the Hammond Postulate to speculate on the extent of bond formation and bond cleavage in the transition state.

The hydrogen atom abstraction step in the free radical bromination of methane is endothermic. Use the Hammond Postulate to speculate on the extent of bond formation and bond cleavage in the transition state.

What reactive intermediate is formed when CHBr3 is treated with hydroxide or when diazomethane is irradiated?

Provide the structure of the transition state in the first propagation step of the free radical chlorination of ethane.

Given an activation energy of 15 kcal/mol, use the Arrhenius equation to estimate how much faster the reaction will occur if the temperature is increased from

Which of the presented mechanisms would be the most energetically favorable and thus the most likely mechanism to actually occur for the following free radical chain reaction? (bond dissociation energies - H-H = 104 kcal/mol; Cl-Cl = 58 kcal/mol; H-Cl = 103 kcal/mol) H2 + Cl2 2 HCl

Provide the major organic product that results when 2,2,4-trimethylpentane is subjected to free radical bromination.

Chlorination of methane can result in a mixture of chlorinated products. What experimental conditions should be used to favor the production of chloromethane over the other chlorinated products?

If the percentage of the axial onformer (on the product side of the reaction) is 42%, what is the ΔG° (in kJ/mol) for the reaction at 25°C? [R = 8.314 J/K∙ mol]

Consider the conversion of X to Z through the sole intermediate Y. Given the reaction-energy diagram shown below, which step is the rate-limiting step? Explain your reasoning.

In an exothermic reaction, are stronger bonds broken and weaker bonds formed or are weaker bonds broken and stronger bonds formed?

Which of the following is a propagation step in the free radical chlorination of dichloromethane?

When acetaldehyde (CH3CHO) is deprotonated, the resulting anion is stabilized by resonance. Draw the major resonance contributing forms of this anion.

How many distinct monochlorinated products can result when isobutane is subjected to free radical chlorination?

When light is shined on a mixture of chlorine and chloromethane, carbon tetrachloride is one of the components of the final reaction mixture. Propose a series of mechanistic steps which explain this observation.

What is the CCC bond angle in (CH3)3C+?

Draw the product of the monochlorination of methane with Cl2 in the presence of light or heat.

The difference in energy between reactants and the transition state is known as ________.

Structure and Bonding

Acids and Bases; Functional Groups

Structure and Stereochemistry of Alkanes

Stereochemistry

Alkyl Halides; Nucleophilic Substitution

Structure and Synthesis of Alkenes; Elimination

Reactions of Alkenes

Structure and Synthesis of Alcohols

Reactions of Alcohols

Infrared Spectroscopy and Mass Spectrometry

Nuclear Magnetic Resonance Spectroscopy

Ethers, Epoxides, and Thioethers

Conjugated Systems, Orbital Symmetry, and Ultraviolet Spectroscopy

Aromatic Compounds

Reactions of Aromatic Compounds

Ketones and Aldehydes

Amines

Carboxylic Acids

Carboxylic Acid Derivatives

Condensations and Alpha Substitutions of Carboxyl Compounds

Carbohydrates and Nucleic Acids

Amino Acids, Peptides, and Proteins

Lipids

Synthetic Polymers

Filters

If the equilibrium constant (K_eq) of a reaction is 0.5 then which of the following that must be true?

What reactive intermediate is formed when CHBr₃is treated with hydroxide or when diazomethane is irradiated?

Which of the presented mechanisms would be the most energetically favorable and thus the most likely mechanism to actually occur for the following free radical chain reaction? (bond dissociation energies - H-H = 104 kcal/mol; Cl-Cl = 58 kcal/mol; H-Cl = 103 kcal/mol) H₂+ Cl₂2 HCl

When acetaldehyde (CH₃CHO) is deprotonated, the resulting anion is stabilized by resonance. Draw the major resonance contributing forms of this anion.

What is the CCC bond angle in (CH₃)₃C⁺?

Draw the product of the monochlorination of methane with Cl₂ in the presence of light or heat.