Question 1

What is the relationship between the keto and enol forms of acetone, CH3COCH3?

Accepted Answer

A) Same compounds 
B) Diastereomers 
C) Enantiomers 
D) Constitutional isomers 
A) Same compounds 
B) Diastereomers 
C) Enantiomers 
D) Constitutional isomers D

Question 2

In the addition of HBr to 1-butyne, the nucleophile in the first step of the mechanism is:

Accepted Answer

A) The Csp-H1s bond of 1-butyne. 
B) The C-C triple bond of 1-butyne. 
C) The H atom in HBr. 
D) The Br ion. 
A) The Csp-H1s bond of 1-butyne. 
B) The C-C triple bond of 1-butyne. 
C) The H atom in HBr. 
D) The Br ion. B

Question 3

In the addition of HBr to 1-butyne, the electrophile in the first step of the mechanism is:

Accepted Answer

A) The Csp-H1s bond of 1-butyne. 
B) The C-C triple bond of 1-butyne. 
C) The H atom in HBr. 
D) The Br ion. 
A) The Csp-H1s bond of 1-butyne. 
B) The C-C triple bond of 1-butyne. 
C) The H atom in HBr. 
D) The Br ion. C

Question 4

Which of the following statements about tautomers is true?

Accepted Answer

A) Tautomers differ in the position of a single bond and a hydrogen atom. 
B) Tautomers differ in the position of a double bond and a carbon atom. 
C) Tautomers differ in the position of a double bond and a hydrogen atom. 
D) Tautomers differ in the position of a single bond and a carbon atom. 
A) Tautomers differ in the position of a single bond and a hydrogen atom. 
B) Tautomers differ in the position of a double bond and a carbon atom. 
C) Tautomers differ in the position of a double bond and a hydrogen atom. 
D) Tautomers differ in the position of a single bond and a carbon atom.

Question 5

Which of the following bases can deprotonate acetylene? You are given the pKa values of the conjugate acids in parentheses.

Accepted Answer

A) Only I and II 
B) Only I and III 
C) Only II and III 
D) Only II and IV 
A) Only I and II 
B) Only I and III 
C) Only II and III 
D) Only II and IV

Question 6

Which of the indicated hydrogen in the following compounds is the least acidic?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
A) I 
B) II 
C) III 
D) IV

Question 7

Which method would work the best in accomplishing the following transformation?

Accepted Answer

A) [1] HBr; [2] 2eq.NaNH2 
B) [1] Br2; [2] 2eq.NaNH2 
C) [1] Br2, H2O; [2] NaNH2 
D) [1]BH3, THF; [2] H2O2, NaOH; [3] NaNH2 
A) [1] HBr; [2] 2eq.NaNH2 
B) [1] Br2; [2] 2eq.NaNH2 
C) [1] Br2, H2O; [2] NaNH2 
D) [1]BH3, THF; [2] H2O2, NaOH; [3] NaNH2

Question 8

Which of the following represents a keto-enol tautomeric pair?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
A) I 
B) II 
C) III 
D) IV

Question 9

Rank the following compounds in order of decreasing basicity, putting the most basic first.

Accepted Answer

A) I > II > III 
B) III > II > I 
C) III > I > II 
D) II > III > I 
A) I > II > III 
B) III > II > I 
C) III > I > II 
D) II > III > I

Question 10

Which of the indicated hydrogen in the following compounds is the most acidic?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
A) I 
B) II 
C) III 
D) IV

Question 11

What is (are) the major organic product(s) of the following reaction?

Accepted Answer

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

Question 12

What is the major organic product of the following reaction?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
A) I 
B) II 
C) III 
D) IV

Question 13

Which of the following molecular formulas is consistent with the formula for a molecule containing one alkyne and no other degrees of unsaturation?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
A) I 
B) II 
C) III 
D) IV

Question 14

Which of the following bases cannot deprotonate acetylene? You are given the pKa values of the conjugate acids in parentheses.

Accepted Answer

A) Only I and II 
B) Only I and III 
C) Only II and III 
D) Only II and IV 
A) Only I and II 
B) Only I and III 
C) Only II and III 
D) Only II and IV

Question 15

Which of the following anions is the most basic?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
A) I 
B) II 
C) III 
D) IV

Question 16

Which of the following statements about alkynes is not true?

Accepted Answer

A) Alkynes undergo many addition reactions. 
B) Alkynes are more polarizable than alkenes. 
C) Both p bonds of a C-C triple bond are weaker than a C-C s bond. 
D) The electrons in the p bonds of alkynes are more tightly held than those of alkenes. 
A) Alkynes undergo many addition reactions. 
B) Alkynes are more polarizable than alkenes. 
C) Both p bonds of a C-C triple bond are weaker than a C-C s bond. 
D) The electrons in the p bonds of alkynes are more tightly held than those of alkenes.

Question 17

What is the major organic product of the following reaction?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
A) I 
B) II 
C) III 
D) IV

Question 18

Which of the following statements about the reactions of alkynes is not true?

Accepted Answer

A) Alkynes contain easily broken p bonds. 
B) Alkynes undergo addition reactions. 
C) When alkynes undergo two sequential addition reactions, four new s bonds are formed. 
D) When alkynes undergo two sequential addition reactions, two new s bonds and a p bond are formed. 
A) Alkynes contain easily broken p bonds. 
B) Alkynes undergo addition reactions. 
C) When alkynes undergo two sequential addition reactions, four new s bonds are formed. 
D) When alkynes undergo two sequential addition reactions, two new s bonds and a p bond are formed.

Question 19

Determine the product of the following reaction.

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
A) I 
B) II 
C) III 
D) IV

Question 20

What is the major organic product of the following reaction?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
A) I 
B) II 
C) III 
D) IV

Exam 11: Alkynes

What is the relationship between the keto and enol forms of acetone, CH3COCH3?

In the addition of HBr to 1-butyne, the nucleophile in the first step of the mechanism is:

In the addition of HBr to 1-butyne, the electrophile in the first step of the mechanism is:

Which of the following statements about tautomers is true?

Which of the following bases can deprotonate acetylene? You are given the pKa values of the conjugate acids in parentheses.

Which of the indicated hydrogen in the following compounds is the least acidic?

Which method would work the best in accomplishing the following transformation?

Which of the following represents a keto-enol tautomeric pair?

Rank the following compounds in order of decreasing basicity, putting the most basic first.

Which of the indicated hydrogen in the following compounds is the most acidic?

What is (are) the major organic product(s) of the following reaction?

What is the major organic product of the following reaction?

Which of the following molecular formulas is consistent with the formula for a molecule containing one alkyne and no other degrees of unsaturation?

Which of the following bases cannot deprotonate acetylene? You are given the pKa values of the conjugate acids in parentheses.

Which of the following anions is the most basic?

Which of the following statements about alkynes is not true?

What is the major organic product of the following reaction?

Which of the following statements about the reactions of alkynes is not true?

Determine the product of the following reaction.

What is the major organic product of the following reaction?

Structure and Bonding

Acids and Bases

Introduction to Organic Molecules and Functional Groups

Alkanes

Stereochemistry

Understanding Organic Reactions

Alkyl Halides and Nucleophilic Substitution

Alkyl Halides and Elimination Reactions

Alcohols, Ethers, and Related Compounds

Alkenes

Oxidation and Reduction

Mass Spectrometry and Infrared Spectroscopy

Nuclear Magnetic Resonance Spectroscopy

Radical Reactions

Conjugation, Resonance, and Dienes

Benzene and Aromatic Compounds

Reactions of Aromatic Compounds

Carboxylic Acids and the Acidity of the O-H Bond

Introduction to Carbonyl Chemistry;

Aldehydes and Ketones Nucleophilic Addition

Carboxylic Acids and Derivatives

Substitution Reactions of Carbonyl Compounds at the Alpha-Carbon

Carbonyl Condensation Reactions

Amines

Carbon-Carbon Bond Forming Reactions in Organic Synthesis

Pericyclic Reactions

Carbohydrates

Amino Acids and Proteins

Synthetic Polymers

Lipids

Filters

What is the relationship between the keto and enol forms of acetone, CH₃COCH₃?

Which of the following bases can deprotonate acetylene? You are given the pK_a values of the conjugate acids in parentheses.

Which of the following bases cannot deprotonate acetylene? You are given the pK_a values of the conjugate acids in parentheses.