Question 1

What is the name given to the reaction species that lies at an energy minimum between steps on a reaction energy diagram?

Accepted Answer

A) Transition state 
B) Activation energy 
C) Reactive intermediate 
D) Equilibrium product 
A) Transition state 
B) Activation energy 
C) Reactive intermediate 
D) Equilibrium product

Question 2

Which of the following statements about bond breaking is true?

Accepted Answer

A) Homolysis and heterolysis require energy. 
B) In homolysis,the electrons in the bond are divided unequally. 
C) In heterolysis,the electrons in the bond are divided equally. 
D) Homolysis generates charged intermediates. 
A) Homolysis and heterolysis require energy. 
B) In homolysis,the electrons in the bond are divided unequally. 
C) In heterolysis,the electrons in the bond are divided equally. 
D) Homolysis generates charged intermediates.

Question 3

The equilibrium constant for the conversion of A to D is predicted to be which of the following?

Accepted Answer

A) Keq = 1 
B) Keq eq > 1 
D) Cannot be determined from the information provided 
A) Keq = 1 
B) Keq eq > 1 
D) Cannot be determined from the information provided

Question 4

The conversion of acetyl chloride to methyl acetate occurs via the following two-step mechanism:   What is the rate equation for this reaction if the first step is rate determining?

Accepted Answer

A) Rate = k [acetyl chloride] [-OCH3] 
B) Rate = k [acetyl chloride] 
C) Rate = k [-OCH3] 
D) Rate = k [acetyl chloride] [-OCH3]2 
A) Rate = k [acetyl chloride] [-OCH3] 
B) Rate = k [acetyl chloride] 
C) Rate = k [-OCH3] 
D) Rate = k [acetyl chloride] [-OCH3]2

Question 5

The conversion of acetyl chloride to methyl acetate occurs via the following two-step mechanism:   If the concentrations of both -OCH3 and acetyl chloride were increased 2 times,what would happen to the rate of the reaction?

Accepted Answer

A) Rate would become one-fourth 
B) Rate would increase 4 times 
C) Rate would increase 16 times 
D) Rate would increase 2 times 
A) Rate would become one-fourth 
B) Rate would increase 4 times 
C) Rate would increase 16 times 
D) Rate would increase 2 times

Question 6

Which of the following statements is not true?

Accepted Answer

A) Bond breaking is endothermic. 
B) The bond dissociation energy for bond breaking is always negative. 
C) Bond making is exothermic. 
D) The bond dissociation energy for bond formation is always negative. 
A) Bond breaking is endothermic. 
B) The bond dissociation energy for bond breaking is always negative. 
C) Bond making is exothermic. 
D) The bond dissociation energy for bond formation is always negative.

Question 7

Which of the Keq corresponds to the most negative value of DG°?

Accepted Answer

A) Keq = 1 
B) Keq = 101 
C) Keq = 102 
D) Keq = 103 
A) Keq = 1 
B) Keq = 101 
C) Keq = 102 
D) Keq = 103

Question 8

Which of the following statements about enzymes is true?

Accepted Answer

A) Enzymes increase the activation energy for a reaction. 
B) Enzymes decrease the equilibrium constant. 
C) Enzymes shift the equilibrium to favor the product. 
D) Enzymes lower the transition state for the rate-determining step. 
A) Enzymes increase the activation energy for a reaction. 
B) Enzymes decrease the equilibrium constant. 
C) Enzymes shift the equilibrium to favor the product. 
D) Enzymes lower the transition state for the rate-determining step.

Question 9

Which of the following statements is not true?

Accepted Answer

A) Two reactions can have identical values for DH° but very different Ea values. 
B) The larger the activation energy,the slower the reaction. 
C) DH° determines the height of the energy barrier. 
D) The lower the activation energy,the faster the reaction. 
A) Two reactions can have identical values for DH° but very different Ea values. 
B) The larger the activation energy,the slower the reaction. 
C) DH° determines the height of the energy barrier. 
D) The lower the activation energy,the faster the reaction.

Question 10

Which of the following letters represents DH° for the forward reaction in the following energy diagram?

Accepted Answer

A) A 
B) B 
C) C 
D) D 
A) A 
B) B 
C) C 
D) D

Question 11

The conversion of acetyl chloride to methyl acetate occurs via the following two-step mechanism:   The conversion of acetyl chloride to methyl acetate would be classified as which of the following?

Accepted Answer

A) Addition 
B) Elimination 
C) Substitution 
D) None of these 
A) Addition 
B) Elimination 
C) Substitution 
D) None of these

Question 12

Which reaction is fast and has Keq = 1?

Accepted Answer

A) A 
B) B 
C) C 
A) A 
B) B 
C) C

Question 13

In which reaction is Keq > 1?

Accepted Answer

A) A 
B) B 
C) C 
A) A 
B) B 
C) C

Question 14

If the conversion of A to B is slow and B to C is fast,what is the rate equation for this reaction?

Accepted Answer

A) Rate = k[(CH3)2CHCl][H2O] 
B) Rate = k[(CH3)2CHCl] 
C) Rate = k[(CH3)2CH]+[H2O] 
D) Rate = k[(CH3)2CH]+ 
A) Rate = k[(CH3)2CHCl][H2O] 
B) Rate = k[(CH3)2CHCl] 
C) Rate = k[(CH3)2CH]+[H2O] 
D) Rate = k[(CH3)2CH]+

Question 15

Which reaction is slowest?

Accepted Answer

A) A 
B) B 
C) C 
A) A 
B) B 
C) C

Question 16

Which of the following expressions summarizes the correct relationship between the free energy change,DG°,and the equilibrium constant,Keq?

Accepted Answer

A) Keq > 1 when DG° > 0 B) Keq > 1 when DG° eq eq < 1 when DG° = 0 A) Keq > 1 when DG° > 0 B) Keq > 1 when DG° eq eq < 1 when DG° = 0

Question 17

Which of the following statements is true?

Accepted Answer

A) Fast reactions have small rate constants. 
B) Slow reactions have large rate constants. 
C) A rate equation contains concentration terms for all reactants involved in a one-step mechanism. 
D) A rate equation contains concentration terms for all the reactants involved in a multi-step reaction. 
A) Fast reactions have small rate constants. 
B) Slow reactions have large rate constants. 
C) A rate equation contains concentration terms for all reactants involved in a one-step mechanism. 
D) A rate equation contains concentration terms for all the reactants involved in a multi-step reaction.

Question 18

Which of the following statements about a catalyst is true?

Accepted Answer

A) A catalyst accelerates a reaction by changing the amount of reactant and product at equilibrium. 
B) A catalyst accelerates a reaction by lowering the energy of activation. 
C) A catalyst accelerates a reaction by raising the energy of activation. 
D) A catalyst accelerates a reaction by lowering the equilibrium constant. 
A) A catalyst accelerates a reaction by changing the amount of reactant and product at equilibrium. 
B) A catalyst accelerates a reaction by lowering the energy of activation. 
C) A catalyst accelerates a reaction by raising the energy of activation. 
D) A catalyst accelerates a reaction by lowering the equilibrium constant.

Question 19

Which of the following statements about addition reactions is true?

Accepted Answer

A) Two π bonds are formed. 
B) Two π bonds are broken. 
C) Two σ bonds are formed. 
D) One π bond is formed. 
A) Two π bonds are formed. 
B) Two π bonds are broken. 
C) Two σ bonds are formed. 
D) One π bond is formed.

Question 20

Using the bond dissociation energies given,calculate DH° for the following reaction.

Accepted Answer

A) +108 KJ/mol 
B) -130 KJ/mol 
C) -22 KJ/mol 
D) +22 KJ/mol 
A) +108 KJ/mol 
B) -130 KJ/mol 
C) -22 KJ/mol 
D) +22 KJ/mol

Exam 6: Understanding Organic Reactions

What is the name given to the reaction species that lies at an energy minimum between steps on a reaction energy diagram?

Which of the following statements about bond breaking is true?

The equilibrium constant for the conversion of A to D is predicted to be which of the following?

The conversion of acetyl chloride to methyl acetate occurs via the following two-step mechanism: What is the rate equation for this reaction if the first step is rate determining?

The conversion of acetyl chloride to methyl acetate occurs via the following two-step mechanism: If the concentrations of both -OCH3 and acetyl chloride were increased 2 times,what would happen to the rate of the reaction?

Which of the following statements is not true?

Which of the Keq corresponds to the most negative value of DG°?

Which of the following statements about enzymes is true?

Which of the following statements is not true?

Which of the following letters represents DH° for the forward reaction in the following energy diagram?

The conversion of acetyl chloride to methyl acetate occurs via the following two-step mechanism: The conversion of acetyl chloride to methyl acetate would be classified as which of the following?

Which reaction is fast and has Keq = 1?

In which reaction is Keq > 1?

If the conversion of A to B is slow and B to C is fast,what is the rate equation for this reaction?

Which reaction is slowest?

Which of the following expressions summarizes the correct relationship between the free energy change,DG°,and the equilibrium constant,Keq?

Which of the following statements is true?

Which of the following statements about a catalyst is true?

Which of the following statements about addition reactions is true?

Using the bond dissociation energies given,calculate DH° for the following reaction.

Structure and Bonding

Acids and Bases

Introduction to Organic Molecules and Functional Groups

Alkanes

Stereochemistry

Alkyl Halides and Nucleophilic Substitution

Alkyl Halides and Elimination Reactions

Alcohols,ethers,and Related Compounds

Alkenes and Addition Reactions

Alkynes and Synthesis

Oxidation and Reduction

Radical Reactions

Conjugation, resonance, and Dienes

Benzene and Aromatic Compounds

Reactions of Aromatic Compounds

Introduction to Carbonyl Chemistry; Organometallic Reagents; Oxidation and Reduction

Aldehydes and Ketones - Nucleophilic Addition

Carboxylic Acids and the Acidity of the O-H Bond

Carboxylic Acids and Their Derivatives - Nucleophilic Acyl Substitution

Substitution Reactions of Carbonyl Compounds at the a Carbon

Carbonyl Condensation Reactions

Amines

Carbon-Carbon Bond-Forming Reactions in Organic Synthesis

Pericyclic Reactions

Carbohydrates

Amino Acids and Proteins

Synthetic Polymers

Lipids

Molecular Ion Peaks and Fragmentation Patterns

Analyzing Molecular Motion and Infrared Spectroscopy

Organic Spectroscopy Concepts

Filters

The conversion of acetyl chloride to methyl acetate occurs via the following two-step mechanism: If the concentrations of both ^-OCH₃ and acetyl chloride were increased 2 times,what would happen to the rate of the reaction?

Which of the K_eq corresponds to the most negative value of DG°?

Which reaction is fast and has K_eq= 1?

In which reaction is K_eq > 1?

Which of the following expressions summarizes the correct relationship between the free energy change,DG°,and the equilibrium constant,K_eq?