Question 1

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.

Question 2

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 reaction

Question 3

Which compound would you predict to be highest in energy?

Accepted Answer

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

Question 4

Which of the following statements about the equilibrium constant, Keq, is true?

Accepted Answer

A)  When Keq > 1, the equilibrium favors the reactants.
B)  When Keq 
C)  The size of Keq tells about the position of equilibrium.
D)  For a reaction to be useful, the equilibrium must favor the reactants.

Question 5

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.

Question 6

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.

Question 7

How many transition states and intermediates would the reaction profile have for the reaction shown below?

Accepted Answer

A)  Three transition states and three intermediates
B)  Two transition states and two intermediates
C)  Three transition states and two intermediates
D)  Two transition states and three intermediates

Question 8

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. B

Question 9

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

Question 10

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

Accepted Answer

A)  DG°
B)  DH°
C)  Keq
D)  Ea

Question 11

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.

Question 12

The conversion of acetyl chloride to methyl acetate occurs via the following two-step mechanism:
-OCH3 and acetyl chloride were increased 2 times, what would happen to the rate of the reaction? A) Rate would become one-fourth B) Rate would increase 4 times C) Rate would increase 16 times D) Rate would increase 2 times" class="answers-bank-image d-inline" rel="preload" >
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

Question 13

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.

Question 14

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.

Question 15

Which of the following statements is true?

Accepted Answer

A)  The product is favored in reaction in which DH° is a positive value.
B)  Entropy decreases when an acyclic compound forms a ring.
C)  In homolytic bond cleavage, entropy decreases and favors formation of products.
D)  The starting material is favored in a reaction in which DH° is a negative value.

Question 16

Which reaction is slowest?

Accepted Answer

A)  A
B)  B
C)  C A

Question 17

Calculate Ea for the conversion of C B. a for the conversion of C B.   A) +3 kcal B) +7 kcal C) +9 kcal D) None of these" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  +3 kcal
B)  +7 kcal
C)  +9 kcal
D)  None of these C

Question 18

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 energy

Question 19

Which reaction has a positive DG°, assuming that entropy changes are negligible compared to enthalpy changes?

Accepted Answer

A)  A
B)  B
C)  C

Question 20

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

Accepted Answer

A)  Addition reaction.
B)  Substitution reaction.
C)  Elimination reaction.
D)  Acid-base reaction.

Exam 6: Understanding Organic Reactions

Which of the following statements about a catalyst is true?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which compound would you predict to be highest in energy?

Correct AnswerverifiedShow Answer

Which of the following statements about the equilibrium constant, Keq, is true?

Correct AnswerverifiedShow Answer

Which of the following statements about addition reactions is true?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

How many transition states and intermediates would the reaction profile have for the reaction shown below?

Correct AnswerverifiedShow Answer

Which of the following statements is not true?

Correct AnswerverifiedB

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which of the following statements about substitution reactions is true?

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which of the following statements is true?

Correct AnswerverifiedShow Answer

Which of the following statements is true?

Correct AnswerverifiedShow Answer

Which reaction is slowest?

Correct AnswerverifiedA

Calculate Ea for the conversion of C B.

Correct AnswerverifiedC

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

Correct AnswerverifiedShow Answer

Which reaction has a positive DG°, assuming that entropy changes are negligible compared to enthalpy changes?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Which of the following statements about the equilibrium constant, K_eq, is true?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
B

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

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?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
A

Calculate E_a for the conversion of C B.

Correct Answer
verified
C

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified