Deck 6: An Overview of Organic Reactions

Question 1

Identify the functional groups present in each compound below, and predict the direction of polarity in each.
Identify and predict:
amphetamine

Answer 1

Question 2

Classify each structure below as a nucleophile or electrophile, and briefly explain your choice.
Classify and explain:
azide

Answer 2

Azide ion is a nucleophile because it has a net negative charge (and lots of nonbonding electron electron pairs!).

Question 3

Polarizability:

A) explains a nonpolar carbon−sulfur bond participating in polar reaction.
B) indicates the magnitude of a dipole moment.
C) is larger for smaller atoms with few electrons.
D) is the electric field associated with a polar bond.
E) all of these

Answer 3

explains a nonpolar carbon−sulfur bond participating in polar reaction.

Question 4

Use the first step of the reaction of 2-bromo-2-methylpropane with water, shown below, to answer the following question(s).
In the following generic reaction between a halogen (X) and an alkane (R), which of the following steps occurs slowly due to low concentration of reactants?

A)X⎯X → 2X∙
B)X∙ + R → HX + R∙
C)R∙ + X⎯X → RX + X∙
D)X∙ + R∙ → RX
E)X∙ + X∙ → X⎯X
F)R∙ + R∙ → R⎯R

Question 5

Which of the following correctly compares the two elements in terms of polarizability?

A) S > O
B) F > Br
C) N > P
D) Cl > I

Question 6

Add curved arrows to the following reaction(s) to indicate the flow of electrons in each.
Indicate flow:

Question 7

Use the first step of the reaction of 2-bromo-2-methylpropane with water, shown below, to answer the following question(s).
Refer to instructions. Add curved arrows to indicate electron flow in the first step.

Question 8

The reaction below is commonly used as a laboratory preparation of cyclohexene. Use this reaction to answer the following question(s).
Refer to instructions. If this reaction under a given set of conditions has a K_eq value of 5.67, what percent conversion to the product would be expected?

A) 85%
B) 5.67%
C) 17%
D) 15%
E) nearly 100%

Question 9

In theory, upon reaction with water in the presence of a strong acid, which of the following will produce more than one isomeric product?

A)

B)

C)

D)

E) Both b and d

Question 10

Identify and label the nucleophile and electrophile in each reaction below.
Identify and label:

Question 11

Use the first step of the reaction of 2-bromo-2-methylpropane with water, shown below, to answer the following question(s).
In the following generic reaction between a halogen (X) and an alkane (R), which of the following steps would be considered a chain termination step?

A)X⎯X → 2X∙
B)X∙ + R → HX + R∙
C)R∙ + X⎯X → RX + X∙
D)X∙ + R∙ → RX
E)X∙ + X∙ → X⎯X
F)R∙ + R∙ → R⎯R

Question 12

How many monochlorosubstitution products are possible for 2,3-dimethylbutane?

A) 1
B) 2
C) 4
D) 5
E) 6

Question 13

Classify each structure below as a nucleophile or electrophile, and briefly explain your choice.
Classify and explain:
phenol

Question 14

In an organic reaction, which of the following is most likely to function as only a nucleophile?

A) BF₃
B) (CH₃)₂CH₂NH₂
C) Fe²⁺
D) CH₃CH₂S−
E) both a and c

Question 15

The reaction below is commonly used as a laboratory preparation of cyclohexene. Use this reaction to answer the following question(s).
Refer to instructions. The forward and reverse reactions are classified, respectively, as:

A) addition, elimination
B) elimination, substitution
C) elimination, addition
D) elimination, rearrangement
E) substitution, addition

Question 16

Use the first step of the reaction of 2-bromo-2-methylpropane with water, shown below, to answer the following question(s).
Refer to instructions. Species B is:

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

Question 17

Consider the reaction of 2-bromo-2-methylpropane with water, shown below, to answer the following question(s).
Refer to instructions. This reaction is an example of:

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

Question 18

Which of the following is a characteristic of a polar reaction?

A) symmetrical bond making and breaking
B) one electron from each reactant forms the bond
C) involves a neutral species with an unpaired electron
D) are more common that radical reactions
E) all of these

Question 19

Identify the functional groups present in each compound below, and predict the direction of polarity in each.
Identify and predict:
mustard gas Cl−CH₂CH₂−S−CH₂CH₂−Cl

Question 20

Identify and label the nucleophile and electrophile in each reaction below.
Identify and label:

Question 21

Add curved arrows to the following reaction(s) to indicate the flow of electrons in each.
The structures below show the stepwise bond making and bond breaking in this reaction. Draw curved arrows to show the electron flow that has occurred in each step.

Question 22

Use the second and third steps of the reaction of 2-bromo-2-methylpropane with water, shown below, to answer the following question(s).
Refer to instructions. Draw arrows on the structures above showing electron flow in steps two and three of this reaction.

Question 23

Add curved arrows to the following reaction(s) to indicate the flow of electrons in each.
Indicate flow:

Question 24

Use the reaction energy diagram below to answer the following question(s).
The transition state is found at _____ on the diagram.

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

Question 25

In the reaction below:
a)Label the nucleophile (Nu) and the electrophile (E).
b)Draw arrows on the structures showing electron flow in the reaction.
Label and indicate flow:

Question 26

Match each definition to one of the terms below.
The energy needed by reactants to reach the transition state.

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

Question 27

Match each definition to one of the terms below.
Another term used for a Lewis acid.

A)polarization
B)addition reaction
C)radical reaction
D)electrophile
E)polar reaction
F)substitution
G)nucleophile
H)elimination reaction

Question 28

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

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

Question 29

Match each definition to one of the terms below.
ΔG° = −RT ln K_eq

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

Question 30

Match each definition to one of the terms below.
A reaction where ΔG° is positive.

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

Question 31

Add curved arrows to the following reaction(s) to indicate the flow of electrons in each.
If the yield for the following reaction is 76%, calculate K_eq and predict the sign of ΔG°.

Question 32

Match each definition to one of the terms below.
A reaction that involves a species with an unpaired electron.

A)polarization
B)addition reaction
C)radical reaction
D)electrophile
E)polar reaction
F)substitution
G)nucleophile
H)elimination reaction

Question 33

In the reaction below:
a)Label the nucleophile (Nu) and the electrophile (E).
b)Draw arrows on the structures showing electron flow in the reaction.
Predict the two alcohol addition products obtained by reaction of the following alkene with aqueous acid.

Question 34

In the reaction below:
a)Label the nucleophile (Nu) and the electrophile (E).
b)Draw arrows on the structures showing electron flow in the reaction.
Predict the product of the following reaction of Prostaglandin H₂ by interpreting the flow of electrons as indicated by the curved arrows.

Question 35

Match each definition to one of the terms below.
A species that lies at an energy maximum during an individual step in a reaction.

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

Question 36

Use the reaction energy diagram below to answer the following question(s).
The products are found at _____ on the diagram.

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

Question 37

Add curved arrows to the following reaction(s) to indicate the flow of electrons in each.
Consider the following reaction: a)Assuming that the first step is the slow step, draw and label a qualitative energy diagram for the reaction.
b)If the second step of the reaction were the slow step, briefly explain how the values of ΔG^‡₁, ΔG^‡₂, and ΔG° would change.

Question 38

Use the second and third steps of the reaction of 2-bromo-2-methylpropane with water, shown below, to answer the following question(s).
Refer to instructions. Label the nucleophile, Nu, and the electrophile, E⁺, in the blanks provided under the structures.

Question 39

Use the reaction energy diagram below to answer the following question(s).
The reactants are found at _____ on the diagram.

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