Question 1

Explain why the lowest energy conformation of decane is an extended, or zig-zag conformation.

Accepted Answer

The lowest-energy conformation

Question 2

When a mole of decane undergoes complete combustion, how many moles of water are formed?

Accepted Answer

A)  1 
B)  10 
C)  11 
D)  15.5 
E)  22 
A)  1 
B)  10 
C)  11 
D)  15.5 
E)  22

Question 3

Which has the greatest molar heat of combustion?

Accepted Answer

A)  trans-1,2-dimethylcyclopentane 
B)  cis-1,2-dimethylcyclopentane 
C)  trans-1,3-dimethylcyclopentane 
D)  methylcyclohexane 
E)  cycloheptane 
A)  trans-1,2-dimethylcyclopentane 
B)  cis-1,2-dimethylcyclopentane 
C)  trans-1,3-dimethylcyclopentane 
D)  methylcyclohexane 
E)  cycloheptane

Question 4

In the lowest energy conformation of the compound below, how many alkyl substituents are equatorial?

Accepted Answer

A)  0 
B)  1 
C)  2 
D)  3 
E)  6 
A)  0 
B)  1 
C)  2 
D)  3 
E)  6

Question 5

Provide an acceptable name for the alkane shown below.

Accepted Answer

2,2,3,6-te

Question 6

Given the following heats of combustion per CH2 group within the structure, which cyclic alkane has essentially no angle strain? (Ref: long-chain Alkane = 659 kJ/mol)

Accepted Answer

A)  cyclobutane = 686 kJ/mol 
B)  cyclopentane = 664 kJ/mol 
C)  cyclohexane = 659 kJ/mol 
D)  cycloheptane = 662 kJ/mol 
E)  cyclooctane = 663 kJ/mol 
A)  cyclobutane = 686 kJ/mol 
B)  cyclopentane = 664 kJ/mol 
C)  cyclohexane = 659 kJ/mol 
D)  cycloheptane = 662 kJ/mol 
E)  cyclooctane = 663 kJ/mol

Question 7

Which intermolecular force is primarily responsible for the interactions among alkane molecules?

Accepted Answer

van der Wa

Question 8

Provide an acceptable name for the alkane shown below.

Accepted Answer

3-ethyl-7-

Question 9

What is the major constituent of natural gas?

Accepted Answer

A)  octane 
B)  butane 
C)  propane 
D)  ethane 
E)  methane 
A)  octane 
B)  butane 
C)  propane 
D)  ethane 
E)  methane

Question 10

Draw an acceptable structure for 4-ethyl-6-(1,2-dimethylpropyl)decane.

Accepted Answer

The answer of Draw an acceptable structure for 4-ethyl-6-(1,2-dimethylpropyl)decane....

Question 11

Circle all substituents that would be expected to occupy an axial position in the fused bicyclic structure below.

Accepted Answer

The answer of Circle all substituents that would be expected...

Question 12

Draw the most stable conformation of cis-1,4-dipropylcyclohexane.

Accepted Answer

The answer of Draw the most stable conformation of cis-1,4-dipropylcyclohexane....

Question 13

The energy barrier for carbon-carbon bond rotation in propane is mainly due to ________.

Accepted Answer

A)  angle strain 
B)  bond strain 
C)  muscle strain 
D)  steric strain 
E)  torsion strain 
A)  angle strain 
B)  bond strain 
C)  muscle strain 
D)  steric strain 
E)  torsion strain

Question 14

How many carbons do the primary alkane constituents of gasoline contain?

Accepted Answer

A)  C1-C2 
B)  C3-C4 
C)  C5-C8 
D)  C8-C12 
E)  C12-C16 
A)  C1-C2 
B)  C3-C4 
C)  C5-C8 
D)  C8-C12 
E)  C12-C16

Question 15

Give structures for the three isomers with molecular formula C5H12 and provide the common name of each.

Accepted Answer

Question 16

Provide an acceptable name for the alkane shown below.

Accepted Answer

2-fluoro-7

Question 17

Consider the three isomeric alkanes n-hexane, 2,3-dimethylbutane, and 2-methylpentane. Which of the following correctly lists these compounds in order of increasing boiling point?

Accepted Answer

A)  2,3-dimethylbutane < 2-methylpentane < n-hexane 
B)  2-methylpentane < n-hexane < 2,3-dimethylbutane 
C)  2-methylpentane < 2,3-dimethylbutane < n-hexane 
D)  n-hexane < 2-methylpentane < 2,3-dimethylbutane 
E)  n-hexane < 2,3-dimethylbutane < 2-methylpentane 
A)  2,3-dimethylbutane < 2-methylpentane < n-hexane 
B)  2-methylpentane < n-hexane < 2,3-dimethylbutane 
C)  2-methylpentane < 2,3-dimethylbutane < n-hexane 
D)  n-hexane < 2-methylpentane < 2,3-dimethylbutane 
E)  n-hexane < 2,3-dimethylbutane < 2-methylpentane

Question 18

Among the butane conformers, which occur at energy minima on a graph of potential energy versus dihedral angle?

Accepted Answer

A)  gauche only 
B)  eclipsed and totally eclipsed 
C)  gauche and anti 
D)  eclipsed only 
E)  anti only 
A)  gauche only 
B)  eclipsed and totally eclipsed 
C)  gauche and anti 
D)  eclipsed only 
E)  anti only

Question 19

If a monocyclic alkane hydrocarbon contains n carbon atoms, how many hydrogen atoms must it also contain?

Accepted Answer

A)  n 
B)  2n 
C)  n + 2 
D)  2n + 2 
E)  n - 2 
A)  n 
B)  2n 
C)  n + 2 
D)  2n + 2 
E)  n - 2

Question 20

In the lowest energy conformation of the compound below, how many alkyl substituents are axial?

Accepted Answer

A)  0 
B)  1 
C)  2 
D)  3 
E)  6 
A)  0 
B)  1 
C)  2 
D)  3 
E)  6

Exam 3: Structure and Stereochemistry of Alkanes

Explain why the lowest energy conformation of decane is an extended, or zig-zag conformation.

When a mole of decane undergoes complete combustion, how many moles of water are formed?

Which has the greatest molar heat of combustion?

In the lowest energy conformation of the compound below, how many alkyl substituents are equatorial?

Provide an acceptable name for the alkane shown below.

Given the following heats of combustion per CH2 group within the structure, which cyclic alkane has essentially no angle strain? (Ref: long-chain Alkane = 659 kJ/mol)

Which intermolecular force is primarily responsible for the interactions among alkane molecules?

Provide an acceptable name for the alkane shown below.

What is the major constituent of natural gas?

Draw an acceptable structure for 4-ethyl-6-(1,2-dimethylpropyl)decane.

Circle all substituents that would be expected to occupy an axial position in the fused bicyclic structure below.

Draw the most stable conformation of cis-1,4-dipropylcyclohexane.

The energy barrier for carbon-carbon bond rotation in propane is mainly due to ________.

How many carbons do the primary alkane constituents of gasoline contain?

Give structures for the three isomers with molecular formula C5H12 and provide the common name of each.

Provide an acceptable name for the alkane shown below.

Consider the three isomeric alkanes n-hexane, 2,3-dimethylbutane, and 2-methylpentane. Which of the following correctly lists these compounds in order of increasing boiling point?

Among the butane conformers, which occur at energy minima on a graph of potential energy versus dihedral angle?

If a monocyclic alkane hydrocarbon contains n carbon atoms, how many hydrogen atoms must it also contain?

In the lowest energy conformation of the compound below, how many alkyl substituents are axial?

Structure and Bonding

Acids and Bases; Functional Groups

The Study of Chemical Reactions

Stereochemistry

Alkyl Halides; Nucleophilic Substitution

Structure and Synthesis of Alkenes; Elimination

Reactions of Alkenes

Structure and Synthesis of Alcohols

Reactions of Alcohols

Infrared Spectroscopy and Mass Spectrometry

Nuclear Magnetic Resonance Spectroscopy

Ethers, Epoxides, and Thioethers

Conjugated Systems, Orbital Symmetry, and Ultraviolet Spectroscopy

Aromatic Compounds

Reactions of Aromatic Compounds

Ketones and Aldehydes

Amines

Carboxylic Acids

Carboxylic Acid Derivatives

Condensations and Alpha Substitutions of Carboxyl Compounds

Carbohydrates and Nucleic Acids

Amino Acids, Peptides, and Proteins

Lipids

Synthetic Polymers

Filters

Given the following heats of combustion per CH₂ group within the structure, which cyclic alkane has essentially no angle strain? (Ref: long-chain Alkane = 659 kJ/mol)

Give structures for the three isomers with molecular formula C₅H₁₂ and provide the common name of each.