Deck 5: Alkenes Thermodynamics and Kinetics

Question 1

Which of the curved arrows are correct for this reaction?

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

Answer 1

A
B
C
D

Question 2

Name the following compound:
$\mathrm { H } _ { 2 } \mathrm { C } = \mathrm { CHCH } _ { 2 } \mathrm { I }$

A) vinyl iodide
B) allyl iodide
C) 1-iodo-2-propene
D) iodomethylethene
E) 2 -iodo-1-propene

Answer 2

allyl iodide

Question 3

Which of the curved arrows are correct for this reaction?

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

Answer 3

B
C

Question 4

Which set of curved arrows correctly shows the flow of electrons in this reaction?

A)
B)
C)
D)

Question 5

Which of the following statements about ethene C₂H₄, is not correct?

A) The H-C-H bond angles are approximately 109.5°.
B) All of the hydrogen atoms are in the same plane.
C) It has five sigma bonds.
D) The carbon atoms are sp² hybridized.
E) The $\mathrm { H } - \mathrm { C } - \mathrm { H }$ bond angles are approximately 120°.

Question 6

Name the following compound:

A) 2-methyl-2,4-pentadiene
B) 4-methyl-1,4-pentadiene
C) 2-methylene-4-pentene
D) 4-methylene-2-pentene
E) 2-methyl-1,4-pentadiene

Question 7

Which of the curved arrows are correct for this reaction?

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

Question 8

How many transition states are in the following reaction coordinate diagram?

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

Question 9

Name the following compound:

A) 7 -chloro-3-ethyl-4-methyl-3-heptene
B) 1-chloro-5-ethyl-4-methyl-3-heptene
C) 1-chloro-3-pentenyl-2-pentene
D) cis-7-chloro-3-ethyl-4-methyl-3-heptene
E) trans- 7 -chloro-3-ethyl-4-methyl-3-heptene

Question 10

Which of the following is vinyl chloride?

A) $\mathrm { CH } _ { 3 } \mathrm { CH } _ { 2 } \mathrm { Cl }$
B) $\mathrm { CH } _ { 2 } = \mathrm { CHCH } _ { 2 } \mathrm { Cl }$
C) $\mathrm { CH } _ { 2 } = \mathrm { CHCl }$
D)

E)

Question 11

What is the name of the following compound?

A) 5-methylcyclohexene
B) 4-methylcyclohexene
C) 1-methyl-3-cyclohexene
D) 1-methyl-4-cyclohexene
E) methylcyclohexene

Question 12

Which of the curved arrows are correct for this reaction?

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

Question 13

Name the following compound:

A) 2-ethyl-1-pentene
B) 2-propyl-1-butene
C) 3-methylenehexane
D) 3-methyl-3-hexene
E) ethyl propyl ethene

Question 14

How many carbons are in the planar double-bond system of 3-methylcyclopentene?

A) 0
B) 1
C) 2
D) 3
E) 4

Question 15

Which of the following statements about propene $\mathrm { CH } _ { 3 } \mathrm { CH } = \mathrm { CH } _ { 2 }$ , is correct?

A) All nine atoms lie in the same plane.
B) The compound has a cis and trans isomer.
C) It is a Lewis acid.
D) It has eight sigma bonds.
E) All the carbon atoms are $s p ^ { 2 }$ hybridized.

Question 16

What is the following compound's common name?

A) t-butylene
B) sec-butylene
C) isobutylene
D) butylene
E) methylpropylene

Question 17

What is the systematic name of the following compound?

A) 2-methyl-1-butene
B) isopentene
C) 2-methybutene
D) 2-ethylpropene
E) 3-methyl-3-butene

Question 18

Name the following compound:

A) 4-chlorocyclohexene
B) 1-chloro-3-cyclohexene
C) 1-chloro-3-cycloheptene
D) 4-chlorocycloheptane
E) 4-chlorocycloheptene

Question 19

Which of the following is not a nucleophile?

A)H⁺
B) Br^-
C) NH₃
D)

E) CH₃OCH₃

Question 20

Which of the following is not an electrophile?

A) $\mathrm { H } ^ { + }$
B) ${ } ^ { + } \mathrm { CH } _ { 3 }$
C) ${ } ^ { + } \mathrm { NO } _ { 2 }$
D) $\mathrm { Fe } ^ { 3 + }$
E) $\mathrm { CH } _ { 2 } = \mathrm { CH } _ { 2 }$

Question 21

Which of the following describes the reaction shown below?
$\mathrm { CH } _ { 2 } = \mathrm { CH } _ { 2 } + \mathrm { HBr } \longrightarrow \mathrm { CH } _ { 3 } \mathrm { CH } _ { 2 } \mathrm { Br } + \text { heat }$

A) $\Delta H ^ { \circ } > 0 \text { and } \Delta S ^ { \circ } > 0$
B) $\Delta H ^ { \circ } > 0 \text { and } \Delta S ^ { \circ } < 0$
C) $\Delta H ^ { \circ } < 0 \text { and } \Delta S ^ { \circ } > 0$
D) $\Delta H ^ { \circ } < 0 \text { and } \Delta S ^ { \circ } < 0$
E) $\Delta H ^ { \circ } = \Delta S ^ { \circ } = 0$

Question 22

Draw the structure of vinyl bromide.

Question 23

An increase in which of the following will occur if the reaction temperature is increased?
I. energy of activation
II) collision frequency
III) fraction of collisions with sufficient energy

A) I and II
B) I and III
C) II and III
D) I, II, and III
E) I

Question 24

Name the following compound:

Question 25

Draw the structure of 1,3-cyclopentadiene.

Question 26

The Gibbs free energy shows that the free energy $\Delta G ^ { \circ }$ ° ________.

A) increases as both Keq and T increase
B) increases most when Keq increases and T decreases
C) increases most when Keq decreases and T increases
D) increases as both Keq and T decrease
E) increases as reactant concentrations increase

Question 27

Name the following compound:

Question 28

Which step has the greatest activation energy in the reverse direction?

A) A going to C
B) C going to E
C) E going to G
D) E going to C
E) C going to A

Question 29

Which of the following describes the reaction whose reaction coordinate diagram is shown below?

A) endergonic with no transition state
B) exergonic with no transition state
C) endergonic with a transition state
D) exergonic with a transition state
E) endergonic with an intermediate

Question 30

Name the following compound:

Question 31

Which of the following describes intermediates $\text { and/or }$ transition states?

A) Transition states occur at minima on reaction coordinate diagrams.
B) Both transition states and intermediates occur at maxima on reaction coordinate diagrams.
C) An intermediate is always produced after the rate-determining step of a reaction mechanism.
D) Transition states have partially formed bonds whereas intermediates have fully formed bonds.
E) none of the above

Question 32

An increase in which of the following results in a decrease in the rate of a reaction?

A) temperature
B) concentration
C) collision frequency
D) energy of activation
E) fraction of collisions with proper orientation

Question 33

Which of the following contributes to make $\Delta G ^ { \circ }$ ° more negative?

A) use of a catalyst
B) a more positive $\Delta H ^ { \circ }$
C) a more positive $\Delta S ^ { \circ }$
D) a larger rate constant
E) none of the above

Question 34

Name the following compound:

Question 35

What is the value of $\Delta H ^ { \circ } \text { in } \mathrm { kcal } / \mathrm { mol }$ for the reaction shown below?
$\left( \mathrm { CH } _ { 3 } \right) _ { 3 } \mathrm { C } - \mathrm { H } + \mathrm { Cl } - \mathrm { Cl } \rightarrow \left( \mathrm { CH } _ { 3 } \right) _ { 3 } \mathrm { C } - \mathrm { Cl } + \mathrm { H } - \mathrm { Cl }$
Bond energies are:
$\begin{array} { l } \quad \left( \mathrm { CH } _ { 3 } \right) 3 \mathrm { C } - \mathrm { H } = 91 \mathrm { kcal } / \mathrm { mol } \\\left( \mathrm { CH } _ { 3 } \right) 3 \mathrm { C } - \mathrm { Cl } = 78.5 \mathrm { kcal } / \mathrm { mol } \\\mathrm { Cl } - \mathrm { Cl } = 58 \mathrm { kcal } / \mathrm { mol } \\\mathrm { H } - \mathrm { Cl } = 103 \mathrm { kcal } / \mathrm { mol }\end{array}$

A) +32.5
B) -57.5
C) -32.5
D) +57.5
E) -8.5

Question 36

What is the free energy of activation for reaction $\mathrm { B } \rightarrow \mathrm { A }$ in the following reaction coordinate diagram?

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

Question 37

Name the following compound. Include E or Z if necessary.

Question 38

Draw and name the six alkenes that have molecular formula C₅H₁₀.

Question 39

Name the following compound:

Question 40

What is the hybridization and bond angle for a carbon in ethene?

Question 41

If the temperature of a reaction is doubled, how will the Gibbs free energy of the reaction change?

Question 42

Name the following compound. Include E or Z if necessary.

Question 43

Why do reactions occur at a faster rate as T increases?

Question 44

Under what conditions is ° equal ° for a reaction?

Question 45

Draw the curved arrows to show how CH₃CH=CHCH₃ reacts with HBr to form a carbocation.

Question 46

Which of the following are nucleophiles and which are electrophiles?

Question 47

Draw all constitutional isomers with molecular formula C₄H₈.

Question 48

Draw the structure of two alkenes with molecular formula C₄H₈ that do not have cis-trans isomers.

Question 49

Which is the rate-determining step in the conversion of A to G in the reaction coordinate
diagram shown below?

Question 50

Consider the conversion of C to D via a one-step reaction. The activation energy of this reaction is 3 kcal/mol. The energy difference between D and the transition state of the reaction is 7 kcal/mol. What is the or the reaction?

Question 51

Which letters designate intermediates in the reaction coordinate diagram shown below?

Question 52

What is the free energy of activation of a one-step reaction? How is it related to the rate constant of the reaction?

Question 53

Draw the structure of (Z)-1-chloro-2-methyl-2-butene.

Question 54

Consider the one-step conversion of F to G. Given that the reaction is endergonic by 5 kcal/mol and that the energy difference between G and the transition state for the reaction is 15 kcal/mol, sketch a reaction coordinate diagram for this reaction. Make sure to show how the given energy differences are consistent with your sketch.

Question 55

Based on the following reaction coordinate diagram, which compound, A or C, is formed faster from B? Which is more stable, A or C?

Question 56

Which step has the greatest rate constant in the forward direction in the reaction coordinate
diagram shown below?