Deck 2: Alkanes and Cycloalkanes

Question 1

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

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

Answer 1

heptane

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 approximate C-C-C bond angle in propane?

A)90 ^$\circ$
B)109 ^$\circ$
C)120 ^$\circ$
D)180 ^$\circ$

Answer 3

109 ^$\circ$

Question 4

What is the IUPAC name of the following compound?

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

Question 5

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

Question 6

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

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

Question 7

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 8

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

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

Question 9

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 10

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 11

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 12

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 13

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

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

Question 14

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

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

Question 15

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 16

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

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

Question 17

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

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

Question 18

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

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

Question 19

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 20

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

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

Question 21

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

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

Question 22

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 23

Which of the following cycloalkanes has the least ring strain?

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

Question 24

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

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

Question 25

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 26

Which of the following cycloalkanes has the most ring strain?

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

Question 27

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

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

Question 28

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

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

Question 29

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

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

Question 30

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 31

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

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

Question 32

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

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

Question 33

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

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

Question 34

Which of the following alkanes has the highest boiling point?

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

Question 35

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

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

Question 36

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 37

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 38

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

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

Question 39

Which of the following alkanes has the highest boiling point?

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

Question 40

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 41

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

A)0 ^$\circ$
B)60 ^$\circ$
C)120 ^$\circ$
D)180 ^$\circ$

Question 42

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 43

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

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

Question 44

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

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

Question 45

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 46

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

A)0 ^$\circ$
B)60 ^$\circ$
C)120 ^$\circ$
D)180 ^$\circ$

Question 47

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

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

Question 48

Which of the following substituted cyclohexanes has the most negative value of $\Delta$ G ^$\circ$ 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 49

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 50

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 51

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 52

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 53

Which of the following is the steroid nucleus?

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

Question 54

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

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

Question 55

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 56

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

A)0 ^$\circ$
B)60 ^$\circ$
C)120 ^$\circ$
D)180 ^$\circ$

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 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 59

Which of the following substituted cyclohexanes has the most negative value of $\Delta$ G ^$\circ$ 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

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

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

Question 61

The following Newman projection represents 2-methylhexane.

Question 62

In the following conversion, the conformations are of equal stability.

Question 63

The following pairs of Newman projections represent the same compound but in differing conformations.

Question 64

What is the IUPAC name of the following compound?

Question 65

Match the Newman projection for the conformation of 2-methylbutane to the indicated position on the potential energy diagram. A) B) C)
D)
Conformation A is represented by Roman numeral ____.

Question 66

The tertiary carbon atom in the following structure is indicated by the letter_____.

Question 67

What is the IUPAC name of the following compound?

Question 68

What is the IUPAC name of the following compound?

Question 69

The following structures represent, from left to right, a cis and a trans isomer.

Question 70

What is the IUPAC name of the following compound?

Question 71

In the following structure the positions labeled a and d are equatorial positions.

Question 72

The correct IUPAC name for the following compound is___________________________.

Question 73

Match the Newman projection for the conformation of 2-methylbutane to the indicated position on the potential energy diagram. A) B) C)
D)
Conformation C is represented by Roman numeral ____.

Question 74

Match the Newman projection for the conformation of 2-methylbutane to the indicated position on the potential energy diagram. A) B) C)
D)
Conformation B is represented by Roman numeral ____.

Question 75

The Newman projection of the gauche conformation of 1,2-dichloroethane is shown below.

Question 76

Match the Newman projection for the conformation of 2-methylbutane to the indicated position on the potential energy diagram. A) B) C)
D)
Conformation D is represented by Roman numeral ____.

Question 77

What is the IUPAC name of the following compound?

Question 78

There are four constitutional isomers for the molecular formula C₆H₁₄.

Question 79

The most stable conformation of an alkane occurs when carbon-carbon bonds are staggered and bulky groups are anti.

Question 80

The following structures represent a pair of constitutional isomers.