Question 1

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

Accepted Answer

A)  +3 KJ/mol
B)  -3 KJ/mol
C)  -67 KJ/mol
D)  +70 KJ/molE) B) and C)
F) A) and B)

Question 2

The conversion of acetyl chloride to methyl acetate occurs via the following two-step mechanism: -OCH3 were increased 5 times,what would happen to the rate of the reaction? A) Rate would become one fifth B) Rate would increase 25 times C) Rate would increase 5 times D) Rate would remain unchanged" class="answers-bank-image d-inline" rel="preload" > If the concentration of -OCH3 were increased 5 times,what would happen to the rate of the reaction?

Accepted Answer

A)  Rate would become one fifth
B)  Rate would increase 25 times
C)  Rate would increase 5 times
D)  Rate would remain unchangedE) C) and D)
F) B) and D)

Question 3

Which compound would you predict to be highest in energy?

Accepted Answer

A)  A
B)  B
C)  C
D)  DE) A) and D)
F) A) and C)

Question 4

Which of the Keq corresponds to the lowest value of DG°?

Accepted Answer

A)  Keq = 10-3
B)  Keq = 10-2
C)  Keq = 10-1
D)  DG° cannot be determined.E) All of the above
F) None of the above

Question 5

Which of the following statements about equilibrium is true?

Accepted Answer

A)  Equilibrium favors the products when the energy of the products is higher than the energy of the reactants.
B)  Equilibrium favors the reactants when the energy of the product is lower than the energy of the reactants.
C)  Equilibrium favors the products when they are less stable than the starting material of a reaction.
D)  Equilibrium favors the products when they are more stable than the starting material of a reaction.E) C) and D)
F) A) and C) D

Question 6

What kind of reaction does the conversion of A to B represent?

Accepted Answer

A)  Acid-base reaction
B)  Elimination reaction
C)  Substitution reaction
D)  Addition reactionE) B) and D)
F) All of the above

Question 7

Which of the following statements is not true?

Accepted Answer

A)  In polar reactions,a nucleophile reacts with an electrophile.
B)  Carbocations are electrophiles.
C)  Carbanions are nucleophiles.
D)  A half-headed curved arrow shows the movement of an electron pair.E) C) and D)
F) A) and B)

Question 8

What kind of reaction does the conversion of A to D represent?

Accepted Answer

A)  Addition reaction
B)  Substitution reaction
C)  Elimination reaction
D)  Oxidation-reduction reactionE) A) and D)
F) A) and B)

Question 9

A decrease in which of the following results in an increase in the rate of a chemical reaction?

Accepted Answer

A)  Energy of activation
B)  Concentration
C)  Temperature
D)  Kinetic energyE) B) and D)
F) A) and B)

Question 10

Which of the following statements about a two-step reaction mechanism is true?

Accepted Answer

A)  The transition states are located at energy minima.
B)  Each step is characterized by its own value of DH° and Ea.
C)  The rate-determining step has the lower energy transition state.
D)  The reactive intermediate is located at an energy maximum.E) C) and D)
F) None of the above

Question 11

The symbol hν stands for ________ in a chemical reaction.

Accepted Answer

A)  light
B)  heat
C)  reactant
D)  productE) B) and D)
F) C) and D)

Question 12

Which of the following statements about elimination reactions is true?

Accepted Answer

A)  Two σ bonds are broken.
B)  Two σ bonds are formed.
C)  Two π bonds are broken.
D)  Two π bonds are formed.E) None of the above
F) B) and C)

Question 13

What type of reaction does the following conversion represent?

Accepted Answer

A)  Addition reaction
B)  Elimination reaction
C)  Substitution reaction
D)  Oxidation-reduction reactionE) None of the above
F) A) and B) B

Question 14

How many transition states are present in the reaction in the energy diagram?

Accepted Answer

A)  0
B)  1
C)  2
D)  3E) A) and D)
F) All of the above

Question 15

Which of the following statements is true?

Accepted Answer

A)  The size of the activation energy tells us about the reaction mechanism.
B)  The size of the activation energy tells us about the reaction rate.
C)  A slow reaction has low activation energy.
D)  A fast reaction has high activation energy.E) B) and D)
F) B) and C)

Question 16

What type of bond cleavage takes place in/what type of intermediate is produced in the following reaction?

Accepted Answer

A)  Homolysis/Radical
B)  Homolysis/Carbocation
C)  Heterolysis/Carbocation
D)  Heterolysis/CarbanionE) C) and D)
F) None of the above

Question 17

Which of the following reaction quantities will have an effect on reaction rate?

Accepted Answer

A)  DG°
B)  DH°
C)  Keq
D)  EaE) A) and B)
F) C) and D) D

Question 18

Which of the following statements about substitution reactions is true?

Accepted Answer

A)  Substitution reactions involve π bonds.
B)  Substitution reactions involve σ bonds.
C)  One σ bond breaks and another forms at a different carbon atom.
D)  One π bond breaks and another forms at the same carbon atom.E) A) and B)
F) None of the above

Question 19

What kind of reaction does the conversion of A to B represent?

Accepted Answer

A)  Addition reaction
B)  Elimination reaction
C)  Substitution reaction
D)  Oxidation-reduction reactionE) A) and B)
F) C) and D)

Question 20

Which of the following statements about bond breaking is not true?

Accepted Answer

A)  Homolysis generates uncharged reactive intermediates with unpaired electrons.
B)  Homolysis require energy but heterolysis does not require energy.
C)  Heterolysis generates charged intermediates.
D)  Heterolysis involves unequal sharing of bonding electrons by atoms.E) All of the above
F) A) and B)

Exam 6: Understanding Organic Reactions

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

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The conversion of acetyl chloride to methyl acetate occurs via the following two-step mechanism: If the concentration of -OCH3 were increased 5 times,what would happen to the rate of the reaction?

Correct AnswerverifiedShow Answer

Which compound would you predict to be highest in energy?

Correct AnswerverifiedShow Answer

Which of the Keq corresponds to the lowest value of DG°?

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Which of the following statements about equilibrium is true?

Correct AnswerverifiedD

What kind of reaction does the conversion of A to B represent?

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Which of the following statements is not true?

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What kind of reaction does the conversion of A to D represent?

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A decrease in which of the following results in an increase in the rate of a chemical reaction?

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Which of the following statements about a two-step reaction mechanism is true?

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The symbol hν stands for ________ in a chemical reaction.

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Which of the following statements about elimination reactions is true?

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What type of reaction does the following conversion represent?

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How many transition states are present in the reaction in the energy diagram?

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Which of the following statements is true?

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What type of bond cleavage takes place in/what type of intermediate is produced in the following reaction?

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Which of the following reaction quantities will have an effect on reaction rate?

Correct AnswerverifiedD

Which of the following statements about substitution reactions is true?

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What kind of reaction does the conversion of A to B represent?

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Which of the following statements about bond breaking is not true?

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The conversion of acetyl chloride to methyl acetate occurs via the following two-step mechanism: If the concentration of ^-OCH₃ were increased 5 times,what would happen to the rate of the reaction?

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Which of the K_eq corresponds to the lowest value of DG°?

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D

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B

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D

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