Deck 2: Alkanes and Cycloalkanes

Question 1

How many constitutional isomers are there with the molecular formula C₄H₁₀?

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

Answer 1

2

Question 2

What is the correct assignment of common names for the following molecules?

A) i = butane; ii = neopentane; iii = isopentane
B) i = neobutane; ii = isobutane; iii = pentane
C) i = butane; ii = isobutane; iii = isopentane
D) i = butane; ii = isobutane; iii = neopentane

Answer 2

i = butane; ii = isobutane; iii = neopentane

Question 3

What is the IUPAC name of the following compound?

A) 2,2-dimethyl-4-ethylheptane
B) 4-ethyl-2,2-dimethyl-heptane
C) 6,6-dimethyl-4-ethylheptane
D) 4-ethyl-6,6-dimethyl-heptane

Answer 3

4-ethyl-2,2-dimethyl-heptane

Question 4

Approximately how long is a C-C single bond of an alkane?

A) 111 pm
B) 134 pm
C) 142 pm
D) 153 pm

Question 5

Which of the following compounds has only 1 $\degree$ and 3 $\degree$ carbon atoms?

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

Question 6

What is the IUPAC name of the following compound?

A) 5,5-dimethyl-3-ethylheptane
B) 5-ethyl-3,3-dimethyl-heptane
C) 3,3-dimethyl-5-ethylheptane
D) 3-ethyl-5,5-dimethyl-heptane

Question 7

What is the name of the linear hydrocarbon with the molecular formula C₇H₁₆?

A) hexane
B) heptane
C) decane
D) undecane

Question 8

What is the approximate C-C-C bond angle in propane?

A) 90 $\degree$
B) 109 $\degree$
C) 120 $\degree$
D) 180 $\degree$

Question 9

Which of the following compounds has 1 $\degree$ , 2 $\degree$ , 3 $\degree$ and 4 $\degree$ carbon atoms?

A) hexane
B) 2-methylhexane
C) 2,2-dimethylhexane
D) 2,2,3-trimethylhexane

Question 10

What is the IUPAC name of the following compound?

A) 2,4-dimethyl-3-isopropyl-pentane
B) 3-isopropyl-1,5-dimethylpentane
C) 3-isopropyl-2,4-dimethylpentane
D) triisopropylmethane

Question 11

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

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

Question 12

What is the IUPAC name of the following compound?

A) 3-propylpentane
B) 1,1-diethylpropane
C) 3-ethylhexane
D) isooctane

Question 13

How many constitutional isomers are there with the molecular formula C₆H₁₄?

A) 3
B) 4
C) 5
D) 8

Question 14

What is the IUPAC name of the following compound?

A) 2-isopropyl-5-methylpentane
B) 5-isopropyl-2-methylpentane
C) 2,3,5-trimethylhexane
D) 1,2-diisopropylpropane

Question 15

What is the correct assignment of common names for the following molecules?

A) i = pentane; ii = isopentane; iii = neopentane
B) i = neopentane; ii = isopentane; iii = pentane
C) i = pentane; ii = neopentane; iii = isopentane
D) i = neopentane; ii = pentane; iii = isopentane

Question 16

How many hydrogen atoms are there in nonane, the linear hydrocarbon with nine carbon atoms?

A) 16
B) 18
C) 20
D) 22

Question 17

How many hydrogen atoms are there in dodecane, the linear hydrocarbon with twelve carbon atoms?

A) 12
B) 20
C) 24
D) 26

Question 18

What is the IUPAC name of the following compound?

A) 2-ethyl-4-methylpentane
B) 2,4-dimethylhexane
C) 3,5-dimethylhexane
D) 1,1,3-trimethylpentane

Question 19

What is the IUPAC name of the following compound?

A) 1-isopropyl-4,6-dimethylcyclohexane
B) 1-isopropyl-2,4-dimethylcyclohexane
C) 4-isopropyl-1,3-dimethylcyclohexane
D) 4-isopropyl-1,5-dimethylcyclohexane

Question 20

What is the name of the linear hydrocarbon with the molecular formula C₁₁H₂₄?

A) heptane
B) decane
C) undecane
D) eicosane

Question 21

Which of the following cycloalkanes has the most ring strain?

A) cyclopropane
B) cyclobutane
C) cyclopentane
D) cyclohexane

Question 22

Which of the following alkanes has the highest boiling point?

A) propane
B) butane
C) pentane
D) hexane

Question 23

Which of the following Newman projections represents the most stable conformation of 2,3-dimethylbutane?

A) 1
B) 2
C) 3
D) 4

Question 24

Which of the following alkanes has the highest boiling point?

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

Question 25

Which of the following Newman projections represents the most stable conformation of 2-methylbutane?

A) 1
B) 2
C) 3
D) 4

Question 26

What is the IUPAC name for the following compound?

A) bicyclo[5.4.3]octane
B) bicyclo[3.2.1]octane
C) bicyclo[3.2.1]hexane
D) bicyclo[2.2.1]octane

Question 27

Which of the following structures represents trans-1,2-dimethylcyclohexane?

A) 1
B) 2
C) 3
D) 4

Question 28

What is the IUPAC name of the following compound?

A) trans-1-isopropyl-4-methylcyclohexane
B) cis-1-isopropyl-4-methylcyclohexane
C) cis-2-isopropyl-5-methylcyclohexane
D) cis-1-tert-butyl-4-methylcyclohexane

Question 29

Which one of the following structures represents a different compound from the other three?

A) 1
B) 2
C) 3
D) 4

Question 30

What is the IUPAC name of the following compound?

A) 1-methylbicyclo[2.2.1]heptane
B) 2-methylbicyclo[2.2.1]heptane
C) 3-methylbicyclo[2.2.1]heptane
D) 4-methylbicyclo[2.2.1]heptane

Question 31

What is the IUPAC name of the following compound?

A) trans-1-isopropyl-4-methylcyclopentane
B) cis-1-tert-butyl-2-methylcyclopentane
C) trans-1-tert-butyl-2-methylcyclopentane
D) cis-1-isopropyl-2-methylcyclopentane

Question 32

Which of the following Newman projections represents 2,4-dimethylpentane?

A) 1
B) 2
C) 3
D) 4

Question 33

Which of the following Newman projections does not represent 2-methylhexane?

A) 1
B) 2
C) 3
D) 4

Question 34

What is the IUPAC name for the following compound?

A) cycloheptane
B) bicyclo[3.2.0]heptane
C) bicyclo[5.4]heptane
D) cyclobutylcyclopentane

Question 35

Which one of the following structures represents a different compound from the other three?

A) 1
B) 2
C) 3
D) 4

Question 36

Which of the following is the most stable conformation of trans-1-ethyl-3-methylcyclohexane?

A) 1
B) 2
C) 3
D) 4

Question 37

Which of the following cycloalkanes has the least ring strain?

A) cyclopropane
B) cyclopentane
C) cyclohexane
D) cycloheptane

Question 38

Which of the following is the most stable conformation of cis-1-isopropyl-3-methylcyclohexane?

A) 1
B) 2
C) 3
D) 4

Question 39

What is the IUPAC name of the following compound?

A) bicyclo[4.3]nonane
B) bicyclo[4.3.0]nonane
C) bicyclo[6.5]nonane
D) bicyclo[6.5.0]nonane

Question 40

Which of the following structures represents trans-1,3-dimethylcyclohexane?

A) 1
B) 2
C) 3
D) 4

Question 41

Which of the following statements is not true regarding the conformation of substituted cyclohexanes?

A) ring inversion of cyclohexane between two chair conformations takes place via a boat conformation
B) substituted cyclohexanes are destabilized by 1,3-diaxial interactions
C) the boat conformation of cyclohexane is usually more stable than the chair conformation
D) the relative amount of two conformations of substituted cyclohexanes can be determined from the difference in strain energy

Question 42

Which of the following statements is not true?

A) Combustion of an alkane is an exothermic reaction.
B) The heat of combustion of propane is three times that of methane.
C) The constitutional isomers of C₇H₁₆ have different heats of combustion from one another
D) The products of combustion of an alkane are H₂O and CO₂.

Question 43

Which of the following cycloalkanes has the smallest heat of combustion per carbon atom?

A) cyclopropane
B) cyclopentane
C) cyclohexane
D) cycloheptane

Question 44

Which of the following substituted cyclohexanes has the most negative value of DG $\degree$ for ring flipping from the conformation in which the substituent is axial to the one where it is equatorial?

A) methylcyclohexane
B) chlorocyclohexane
C) isopropylcyclohexane
D) ethynylcyclohexane

Question 45

In which of the following compounds are all of the carbon atoms in the same plane?

A) cyclopropane
B) cyclobutane
C) cyclopentane
D) cyclohexane

Question 46

Which of the following undergoes the most exothermic combustion?

A) octane
B) 2-methylheptane
C) 2,2-dimethylhexane
D) 2,2,3,3-tetramethylbutane

Question 47

Which of the following structures is different from the other three?

A) 1
B) 2
C) 3
D) 4

Question 48

What is the approximate dihedral angle between the two chlorine atoms in the diaxial conformation of trans-1,2-dichlorocyclohexane?

A) 0 $\degree$
B) 60 $\degree$
C) 120 $\degree$
D) 180 $\degree$

Question 49

Which of the following cycloalkanes has the largest heat of combustion per carbon atom?

A) cyclopropane
B) cyclopentane
C) cyclohexane
D) cycloheptane

Question 50

Which of the following cycloalkanes has the largest heat of combustion?

A) cyclopropane
B) cyclobutane
C) cyclopentane
D) cyclohexane

Question 51

What is the approximate dihedral angle between the two chlorine atoms in cis-1,2-dichlorocyclohexane?

A) 0 $\degree$
B) 60 $\degree$
C) 120 $\degree$
D) 180 $\degree$

Question 52

Which of the following compounds can adopt a chair conformation in which there are no axial methyl groups?

A) cis-1,2-dimethylcyclohexane
B) cis-1,3-dimethylcyclohexane
C) trans-1,3-dimethylcyclohexane
D) cis-1,4-dimethylcyclohexane

Question 53

How many moles of molecular oxygen (O₂) are consumed in the complete combustion of one mole of hexane (C₆H₁₄)?

A) 6
B) 9.5
C) 12.5
D) 14

Question 54

Which of the following is the steroid nucleus?

A) 1
B) 2
C) 3
D) 4

Question 55

Which of the following structures is different from the other three?

A) 1
B) 2
C) 3
D) 4

Question 56

What is the approximate dihedral angle between the two chlorine atoms in the diequatorial conformation of trans-1,2-dichlorocyclohexane?

A) 0 $\degree$
B) 60 $\degree$
C) 120 $\degree$
D) 180 $\degree$

Question 57

Which of the following is not true regarding the properties of alkanes?

A) alkanes are nonpolar
B) alkanes burn in air to give H₂O and CO₂
C) alkanes are highly miscible with water
D) the strongest intermolecular force between alkane molecules is the van der Waals interaction

Question 58

Which of the following compounds can adopt a chair conformation in which there are no axial methyl groups?

A) 1,1-dimethylcyclohexane
B) cis-1,2-dimethylcyclohexane
C) trans-1,2-dimethylcyclohexane
D) cis-1,3-dimethylcyclohexane

Question 59

Which of the following substituted cyclohexanes has the most negative value of DG $\degree$ for ring flipping from the conformation in which the substituent is axial to the one where it is equatorial?

A) fluorocyclohexane
B) methylcyclohexane
C) ethylcyclohexane
D) tert-butylcyclohexane

Question 60

How many moles of molecular oxygen (O₂) are consumed in the complete combustion of one mole of octane (C₈H₁₈)?

A) 12.5
B) 13
C) 17
D) 26

Question 61

Provide a Newman projection of the most stable conformation of 3-methylpentane, CH₃CH₂CH(CH₃)CH₂CH₃ looking along the C2-C3 bond.

Question 62

What is the IUPAC name of the following compound?

Question 63

What is the IUPAC name of the following compound?

Question 64

What is the IUPAC name of the following compound?

Question 65

What are the common and IUPAC names of the following compound?

Question 66

Provide a Newman projection of the most stable conformation of 2-methylpentane, (CH₃)₂CHCH₂CH₂CH₃, looking along the C2-C3 bond

Question 67

What is the IUPAC name of the following compound?

Question 68

What is the IUPAC name of the following compound?

Question 69

Provide a line-bond structure of hexanoic acid.

Question 70

What is the IUPAC name of the following compound?

Question 71

Provide a line-bond structure of pentanal.

Question 72

What is the IUPAC name of the following compound?

Question 73

What is the IUPAC name of the following compound?

Question 74

What is the IUPAC name of the following compound?

Question 75

Provide a neatly drawn plot of energy versus dihedral angle for rotation around the C-C bond of ethane.

Question 76

What are the common and IUPAC names of the following compound?

Question 77

Provide a neatly drawn plot of energy versus dihedral angle for rotation around the C2-C3 bond of butane.