Question 1

The conversion of acetyl chloride to methyl acetate occurs via the following two-step mechanism:  What is the rate equation for this reaction if the first step is rate determining?

Accepted Answer

A) Rate = k [acetyl chloride] [-OCH3] 
B) Rate = k [acetyl chloride] 
C) Rate = k [-OCH3] 
D) Rate = k [acetyl chloride] [-OCH3]2

Question 2

Which of the following expressions summarizes the correct relationship between the free energy change,DG°,and the equilibrium constant,Keq?

Accepted Answer

A) Keq > 1 when DG° > 0 
B) Keq > 1 when DG° eq eq < 1 when DG° = 0

Question 3

In which reaction is Keq > 1?

Accepted Answer

A) A 
B) B 
C) C

Question 4

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 5

Which step would most likely have the largest energy of activation?

Accepted Answer

A) Step one 
B) Step two 
C) Step three 
D) It cannot be determined from the information provided

Question 6

The conversion of acetyl chloride to methyl acetate occurs via the following two-step mechanism:  The conversion of acetyl chloride to methyl acetate would be classified as which of the following?

Accepted Answer

A) Addition 
B) Elimination 
C) Substitution 
D) None of these

Question 7

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 8

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 9

Which of the following statements is true?

Accepted Answer

A) Bond dissociation energies increase down a column of the periodic table. 
B) When DH° is positive,more energy is released in forming bonds than is needed to break bonds. 
C) When DH° is negative,more energy is needed to break bonds than is released in forming bonds. 
D) Bond dissociation energies decrease down a column of the periodic table.

Question 10

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 reaction

Question 11

Which reaction is slowest?

Accepted Answer

A) A 
B) B 
C) C

Question 12

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

Accepted Answer

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

Question 13

The symbol hν stands for ________ in a chemical reaction.

Accepted Answer

A) light 
B) heat 
C) reactant 
D) product

Exam 6: Understanding Organic Reactions

The conversion of acetyl chloride to methyl acetate occurs via the following two-step mechanism: What is the rate equation for this reaction if the first step is rate determining?

Which of the following expressions summarizes the correct relationship between the free energy change,DG°,and the equilibrium constant,K_eq?

In which reaction is K_eq > 1?

Which of the following statements is true?

Which step would most likely have the largest energy of activation?

The conversion of acetyl chloride to methyl acetate occurs via the following two-step mechanism: The conversion of acetyl chloride to methyl acetate would be classified as which of the following?

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

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

Which of the following statements is true?

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

Which reaction is slowest?

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

The symbol hν stands for ________ in a chemical reaction.