Deck 6: An Overview of Organic Reactions

Question 1

Exhibit 6-10
Consider the reaction of 2-bromo-2-methylpropane with water,shown below,to answer the following question(s).
​ ​
Diagram 1: The first step of this reaction is shown below.
​ Diagram 2: The second and third steps of the reaction are shown below.
​
Refer to Exhibit 6-10.This reaction is an example of:

A)a substitution reaction.
B)a rearrangement reaction.
C)an elimination reaction.
D)an addition reaction.

Answer 1

a substitution reaction.

Question 2

Exhibit 6-10
Consider the reaction of 2-bromo-2-methylpropane with water,shown below,to answer the following question(s).
​ ​
Diagram 1: The first step of this reaction is shown below.
​ Diagram 2: The second and third steps of the reaction are shown below.
​
Refer to Exhibit 6-10.Using the bond dissociations values in the table below,calculate the ΔH° for the reaction in Diagram 2.Show your calculations for full credit.
Bond
D (kJ/mol)
(CH₃)₃C−Br
263
(CH₃)₃C−OH
380
HO−H
498
H−Br
366

Answer 2

ΔH°
= ΔH° bonds broken − ΔH° bonds formed
= 761 kJ/mol − 746 kJ/mol
= +15 kJ/mol
Bonds Broken
Bonds Formed
(CH₃)₃C−Br
263 kJ/mol
(CH₃)₃C−OH
380 kJ/mol
HO−H
498 kJ/mol
H−Br
366 kJ/mol
761 kJ/mol
746 kJ/mol

Question 3

Exhibit 6-10
Consider the reaction of 2-bromo-2-methylpropane with water,shown below,to answer the following question(s).
​ ​
Diagram 1: The first step of this reaction is shown below.
​ Diagram 2: The second and third steps of the reaction are shown below.
​
Refer to Exhibit 6-10.In Diagram 2,label the nucleophile,Nu,and the electrophile,E⁺,in the blanks provided under the structures.

Answer 3

Question 4

Refer to Exhibit 6-7.Draw a qualitative energy diagram for the reaction (assume that the first step is slower than the second step).Label fully.

Question 5

_____ A reaction where ΔG° is negative.

A)transition state
B)endergonic reaction
C)activation energy
D)standard Gibbs free energy change
E)exergonic reaction
F)reaction intermediate

Question 6

Exhibit 6-10
Consider the reaction of 2-bromo-2-methylpropane with water,shown below,to answer the following question(s).
​ ​
Diagram 1: The first step of this reaction is shown below.
​ Diagram 2: The second and third steps of the reaction are shown below.
​
Refer to Exhibit 6-10.In Diagram 1,add curved arrows to indicate electron flow.

Question 7

Exhibit 6-9
Use the reaction energy diagram below to answer the following question(s).
​
Refer to Exhibit 6-9.The free-energy change for the reaction is indicated at point _____ on the diagram.

Question 8

Exhibit 6-9
Use the reaction energy diagram below to answer the following question(s).
​
Refer to Exhibit 6-9.The products are found at point _____ on the diagram.

Question 9

Exhibit 6-7
Consider this reaction when answering the following question(s):
​
Refer to Exhibit 6-7.This reaction is an example of:

A)a substitution reaction.
B)a rearrangement reaction.
C)an addition reaction.
D)an elimination reaction.

Question 10

The original question has been combined with #21 as part
b.This placeholder question is here to maintain the integrity of the numbering system between the printed copy and ExamView.Therefore,it has been marked "do not use on test" in ExamView's question information dialog.As a result,this placeholder question is automatically prevented from being chosen as a test question.

Question 11

Exhibit 6-10
Consider the reaction of 2-bromo-2-methylpropane with water,shown below,to answer the following question(s).
​ ​
Diagram 1: The first step of this reaction is shown below.
​ Diagram 2: The second and third steps of the reaction are shown below.
​
Refer to Exhibit 6-10.In Diagram 1,Species B is:

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

Question 12

Exhibit 6-7
Consider this reaction when answering the following question(s):
​
Refer to Exhibit 6-7.

A)The structures below show the step-wise bond making and bond breaking in this reaction.Draw curved arrows to show the electron flow that has occurred in each step.

B)Calculate K_eq for the reaction in part
C)Calculate ΔG° for the reaction in part

Question 13

Exhibit 6-9
Use the reaction energy diagram below to answer the following question(s).
​
Refer to Exhibit 6-9.The transition state is found at point _____ on the diagram.

Question 14

_____ ΔG° = −RT ln K_eq

A)transition state
B)endergonic reaction
C)activation energy
D)standard Gibbs free energy change
E)exergonic reaction
F)reaction intermediate

Question 15

Exhibit 6-10
Consider the reaction of 2-bromo-2-methylpropane with water,shown below,to answer the following question(s).
​ ​
Diagram 1: The first step of this reaction is shown below.
​ Diagram 2: The second and third steps of the reaction are shown below.
​
Refer to Exhibit 6-10.The reaction in Diagram 2 is an example of:

A)a pericyclic reaction.
B)a radical reaction.
C)a concerted reaction.
D)a stepwise reaction.

Question 16

Exhibit 6-9
Use the reaction energy diagram below to answer the following question(s).
​
Refer to Exhibit 6-9.The reactants are found at point _____ on the diagram.

Question 17

_____ The energy needed by reactants to reach the transition state.

A)transition state
B)endergonic reaction
C)activation energy
D)standard Gibbs free energy change
E)exergonic reaction
F)reaction intermediate

Question 18

_____ A species that lies at an energy minimum between steps on a reaction.

A)transition state
B)endergonic reaction
C)activation energy
D)standard Gibbs free energy change
E)exergonic reaction
F)reaction intermediate

Question 19

Exhibit 6-9
Use the reaction energy diagram below to answer the following question(s).
​
Refer to Exhibit 6-9.The reaction depicted in this reaction energy diagram can best be described as:

A)a slow exothermic reaction
B)a fast exothermic reaction
C)a slow endothermic reaction
D)a fast endothermic reaction

Question 20

Exhibit 6-10
Consider the reaction of 2-bromo-2-methylpropane with water,shown below,to answer the following question(s).
​ ​
Diagram 1: The first step of this reaction is shown below.
​ Diagram 2: The second and third steps of the reaction are shown below.
​
Refer to Exhibit 6-10.In Diagram 2,draw arrows on the structures showing electron flow.

Question 21

The alkane formed by hydrogenation of (S)-4-methyl-1-hexene is optically active while the one formed by hydrogenation of (S)-3-methyl-1-pentene is not.Explain.

Question 22

Consider the following process. Which of the following correctly applies?

A)termination step
B)unsymmetrical bond formation
C)polar reaction
D)produces a radical

Question 23

Which of the following could act as a nucleophile?

A)HCl
B)CH₃NH₂
C)BF₃
D)CH₃Br

Question 24

Which of the following could act as an electrophile?

A)CN^-
B)NH₂^-
C)NH₃
D)H₃O⁺

Question 25

Consider the following grayscale electrostatic potential map.The regions are labeled as to color. Which atom is the most likely to be attacked by a nucleophile?

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

Question 26

​Write the mechanism of the reaction of trans-2-butene with hydrogen bromide.

Question 27

Exhibit 6-10
Consider the reaction of 2-bromo-2-methylpropane with water,shown below,to answer the following question(s).
​ ​
Diagram 1: The first step of this reaction is shown below.
​ Diagram 2: The second and third steps of the reaction are shown below.
​
Refer to Exhibit 6-10.Based on all of the data presented in Exhibit 6-10,draw a qualitative reaction energy diagram for the reaction of 2-bromo-2-methylpropane with water.The first step is the slowest step of the reaction.Fully label the diagram,including the coordinates.

Question 28

Consider a reaction with the following thermodynamic properties. ΔH° = 77.7 kJ
ΔS° = -35.7 J/(K • mol)
ΔG°= 88.4 kJ
This reaction:

A)will be spontaneous at low temperatures.
B)has bonds in the products that are weaker than the reactants.
C)may have fewer and more complicated molecules in the product.
D)will proceed very slowly.

Question 29

A reaction that establishes equilibrium with almost no reactants present:

A)is exergonic.
B)has a negative ΔG°.
C)has a large Keq.
D)all of the above.

Question 30

Consider the following energy diagram for an enzyme-catalyzed reaction. Which step is probably the slowest?

A)A - C
B)C - E
C)E - G
D)G - I

Question 31

In a polar reaction mechanism,the atom that gives away electrons in a neutral nucleophile will end up as a(n):

A)cation
B)anion
C)radical
D)neutral molecule

Question 32

The following represents the carbocation intermediate in the reaction of an alkene with HBr. Draw the skeletal structure of the possible products and reactants.

Question 33

Consider the following grayscale electrostatic potential map.The regions are labeled as to color. Which atom is the most electron poor?

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

Question 34

What are the major differences between a reaction occurring in flask in the laboratory compared to a reaction occurring in a biological system?

Question 35

Consider the following energy diagram. Which step has the least endergonic ΔG^±?

A)A - C
B)C - E
C)E - G
D)G - I

Question 36

Which of the following compounds would produce a single product when treated with Cl₂ in the presence of ultraviolet radiation?

A)butane
B)2-methylpropane
C)2,2,-dimethylpropane
D)All would produce multiple products.

Question 37

Consider the following energy diagram for an enzyme-catalyzed reaction. How many transition states are involved?

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

Question 38

The enzyme aconitase catalyzes the hydration of the alkene functional group of aconitic acid to give two products,citric acid and isocitric acid.Isocitric acid is optically active;citric acid is not optically active.Based on your knowledge of alkene hydration and optical activity,the structure of citric acid is:

A)
B)
C)
D)cannot be determined

Question 39

A reaction has ΔH° = -14.7 kJ and ΔS° of 35.7 J/(K • mol),will

A)be exergonic.
B)have a positive ΔG°.
C)have a very small K_eq.
D)will proceed rapidly.

Question 40

Consider the following energy diagram for an enzyme-catalyzed reaction. Which step has the least energetic transition state?

A)A - C
B)C - E
C)E - G
D)G - I

Question 41

Write the mechanism of the reaction between hydroxide ion and methyl chloride.​

Question 42

​Write the mechanism of the reaction between water and ammonia.