Question 1

Which of the following statements about the conformations of acyclic alkanes is true?

Accepted Answer

A) Conformations are the same arrangements of atoms that cannot be interconverted by rotation about single bonds. 
B) In the eclipsed conformation, the C-H bonds on one carbon bisect the H-C-H bond angle on the adjacent carbon. 
C) In the staggered conformation, the C-H bonds on one carbon are directly aligned with the C-H bonds on the adjacent carbon. 
D) Rotating the atoms on one carbon by 60° converts an eclipsed conformation into a staggered conformation, and vice versa. 
A) Conformations are the same arrangements of atoms that cannot be interconverted by rotation about single bonds. 
B) In the eclipsed conformation, the C-H bonds on one carbon bisect the H-C-H bond angle on the adjacent carbon. 
C) In the staggered conformation, the C-H bonds on one carbon are directly aligned with the C-H bonds on the adjacent carbon. 
D) Rotating the atoms on one carbon by 60° converts an eclipsed conformation into a staggered conformation, and vice versa. D

Question 2

Which of the following cycloalkanes has the most angle strain?

Accepted Answer

A) Cyclopropane 
B) Cyclobutane 
C) Cyclopentane 
D) Cyclohexane 
A) Cyclopropane 
B) Cyclobutane 
C) Cyclopentane 
D) Cyclohexane A

Question 3

Which of the following compounds has only primary and secondary hydrogen atoms?

Accepted Answer

A) 2-Methylpentane 
B) 2,2,3-Trimethylpentane 
C) 3-Methylpentane 
D) 2,2-Dimethylpentane 
A) 2-Methylpentane 
B) 2,2,3-Trimethylpentane 
C) 3-Methylpentane 
D) 2,2-Dimethylpentane D

Question 4

How many constitutional isomers are there with the molecular formula C5H12?

Accepted Answer

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

Question 5

What is the relation between the following pair of compounds?

Accepted Answer

A) Constitutional isomers 
B) Stereoisomers 
C) Identical molecules 
D) Not isomers of each other 
A) Constitutional isomers 
B) Stereoisomers 
C) Identical molecules 
D) Not isomers of each other

Question 6

What is the name of the alkyl group that contains two carbons in a straight chain and one-carbon branch?

Accepted Answer

A) Ethyl 
B) Propyl 
C) Isopropyl 
D) None of these 
A) Ethyl 
B) Propyl 
C) Isopropyl 
D) None of these

Question 7

What is the common name of the following alkyl group?

Accepted Answer

A) Isobutyl 
B) sec-Butyl 
C) Isopropyl 
D) tert-Butyl 
A) Isobutyl 
B) sec-Butyl 
C) Isopropyl 
D) tert-Butyl

Question 8

Which of the following statements about the conformations of acyclic alkanes is true?

Accepted Answer

A) A staggered conformation with two larger groups 180° from each other is called gauche. 
B) Staggered conformations are at energy maxima and eclipsed conformations are energy minima. 
C) A staggered conformation with two larger groups 60° from each other is called anti. 
D) Gauche conformations are generally higher in energy than anti conformations. 
A) A staggered conformation with two larger groups 180° from each other is called gauche. 
B) Staggered conformations are at energy maxima and eclipsed conformations are energy minima. 
C) A staggered conformation with two larger groups 60° from each other is called anti. 
D) Gauche conformations are generally higher in energy than anti conformations.

Question 9

Which of the following is the most stable conformation of cis-1-ethyl-3-isopropylcyclohexane?

Accepted Answer

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

Question 10

What is the IUPAC name for the following compound?

Accepted Answer

A) Hexylcyclopentane 
B) 1-Hexylcyclopentane 
C) 1-Cyclopentylhexane 
D) 1-Cyclopentylheptane 
A) Hexylcyclopentane 
B) 1-Hexylcyclopentane 
C) 1-Cyclopentylhexane 
D) 1-Cyclopentylheptane

Question 11

What is the hybridization of a carbon atom in an alkane?

Accepted Answer

A) sp3 
B) sp2 
C) sp 
D) p 
A) sp3 
B) sp2 
C) sp 
D) p

Question 12

Which of the following compounds has only primary, secondary, and quaternary carbon atoms?

Accepted Answer

A) Pentane 
B) 2-Methylpentane 
C) 2,2-Dimethylpentane 
D) 2,2,3-Trimethylpentane 
A) Pentane 
B) 2-Methylpentane 
C) 2,2-Dimethylpentane 
D) 2,2,3-Trimethylpentane

Question 13

Which of the following statements about alkanes is not true?

Accepted Answer

A) Alkanes are aliphatic hydrocarbons. 
B) Alkanes contain only C-C and C-H s bonds. 
C) Alkanes are acyclic or cyclic. 
D) Acyclic alkanes have two fewer H atoms than cyclic alkanes with the same number of carbons. 
A) Alkanes are aliphatic hydrocarbons. 
B) Alkanes contain only C-C and C-H s bonds. 
C) Alkanes are acyclic or cyclic. 
D) Acyclic alkanes have two fewer H atoms than cyclic alkanes with the same number of carbons.

Question 14

What is the IUPAC name for the following compound?

Accepted Answer

A) 3-Ethyl-2,7-dimethyl-5-sec-butyldecane 
B) 5-sec-Butyl-3-ethyl-2,7-dimethyldecane 
C) 2,7-Dimethyl-3-ethyl-5-sec-butyldecane 
D) 3-Ethyl-2,7-dimethyl-5-isobutyldecane 
A) 3-Ethyl-2,7-dimethyl-5-sec-butyldecane 
B) 5-sec-Butyl-3-ethyl-2,7-dimethyldecane 
C) 2,7-Dimethyl-3-ethyl-5-sec-butyldecane 
D) 3-Ethyl-2,7-dimethyl-5-isobutyldecane

Question 15

Which of the following is not a conformer of butane?

Accepted Answer

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

Question 16

What is the parent chain for the following compound?

Accepted Answer

A) Hexane 
B) Heptane 
C) Octane 
D) Nonane 
A) Hexane 
B) Heptane 
C) Octane 
D) Nonane

Question 17

Which of the following is the lowest energy conformer of 2,3-dimethybutane?

Accepted Answer

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

Question 18

What is the IUPAC name for the following compound?

Accepted Answer

A) 5-Ethyl-3,6-dimethylheptane 
B) 3-Ethyl-2,5-dimethylheptane 
C) 3-Ethyl-2,5-dimethyloctane 
D) 5-Ethyl-3,6-dimethyloctane 
A) 5-Ethyl-3,6-dimethylheptane 
B) 3-Ethyl-2,5-dimethylheptane 
C) 3-Ethyl-2,5-dimethyloctane 
D) 5-Ethyl-3,6-dimethyloctane

Question 19

Which of the following compounds has primary, secondary, and tertiary hydrogen atoms?

Accepted Answer

A) Pentane 
B) Hexane 
C) 2-Methylpentane 
D) 2,2-Dimethylpentane 
A) Pentane 
B) Hexane 
C) 2-Methylpentane 
D) 2,2-Dimethylpentane

Question 20

What is the IUPAC name for the following compound?

Accepted Answer

A) 3-Ethyl-1-methylcyclohexane 
B) 1-Ethyl-3-methylcyclohexane 
C) 1-Ethyl-3-methylhexane 
D) 3-Ethyl-1-methylhexane 
A) 3-Ethyl-1-methylcyclohexane 
B) 1-Ethyl-3-methylcyclohexane 
C) 1-Ethyl-3-methylhexane 
D) 3-Ethyl-1-methylhexane

Exam 4: Alkanes

Which of the following statements about the conformations of acyclic alkanes is true?

Which of the following cycloalkanes has the most angle strain?

Which of the following compounds has only primary and secondary hydrogen atoms?

How many constitutional isomers are there with the molecular formula C5H12?

What is the relation between the following pair of compounds?

What is the name of the alkyl group that contains two carbons in a straight chain and one-carbon branch?

What is the common name of the following alkyl group?

Which of the following statements about the conformations of acyclic alkanes is true?

Which of the following is the most stable conformation of cis-1-ethyl-3-isopropylcyclohexane?

What is the IUPAC name for the following compound?

What is the hybridization of a carbon atom in an alkane?

Which of the following compounds has only primary, secondary, and quaternary carbon atoms?

Which of the following statements about alkanes is not true?

What is the IUPAC name for the following compound?

Which of the following is not a conformer of butane?

What is the parent chain for the following compound?

Which of the following is the lowest energy conformer of 2,3-dimethybutane?

What is the IUPAC name for the following compound?

Which of the following compounds has primary, secondary, and tertiary hydrogen atoms?

What is the IUPAC name for the following compound?

Structure and Bonding

Acids and Bases

Introduction to Organic Molecules and Functional Groups

Stereochemistry

Understanding Organic Reactions

Alkyl Halides and Nucleophilic Substitution

Alkyl Halides and Elimination Reactions

Alcohols, Ethers, and Related Compounds

Alkenes

Alkynes

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

How many constitutional isomers are there with the molecular formula C₅H₁₂?