Deck 4: Alkanes

Question 1

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

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

Answer 1

2,2-Dimethylpentane

Question 2

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

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

Answer 2

2-Methylpentane

Question 3

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

A)sp³
B)sp²
C)sp
D)p

Answer 3

sp³

Question 4

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

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

Question 5

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

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

Question 6

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

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

Question 7

What is the parent chain for the following compound?

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

Question 8

What is the molecular formula of an alkane that has twenty-three carbon atoms?

A)C₂₃H₄₆
B)C₂₃H₄₈
C)C₂₃H₅₀
D)C₂₃H₄₄

Question 9

What is the parent chain for the following compound?

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

Question 10

Which of the following is not another representation for 2-methylbutane?

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

Question 11

What is the molecular formula of a cycloalkane that has six carbon atoms?

A)C₆H₁₄
B)C₆H₁₀
C)C₆H₁₂
D)C₆H₁₆

Question 12

How many cycloalkane constitutional isomers (excluding stereoisomers)are there with molecular formula C₅H₁₀?

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

Question 13

Which of the following statements about alkanes is not true?

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?

A)4-Ethyl-5-methyloctane
B)4-Methyl-5-ethyloctane
C)4-Methyl-3-propylheptane
D)4-Methyl-5-propyloctane

Question 15

Which of the following statements about alkanes is true?

A)Alkanes are aliphatic hydrocarbons having only C-C and C-H p bonds.
B)Cyclic alkanes have two fewer H atoms than acyclic alkanes with the same number of carbons.
C)Acyclic alkanes contain carbons joined in one or more rings.
D)Acyclic alkanes have the general molecular formula C_nH_2n.

Question 16

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

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

Question 17

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

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

Question 18

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

A)90°
B)109.5°
C)120°
D)180°

Question 19

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

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

Question 20

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

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

Question 21

What is the IUPAC name for the following compound?

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

Question 22

Rank the following alkanes in order of decreasing boiling point,putting the alkane with the highest boiling point first.

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

Question 23

What is the IUPAC name for the following compound?

A)2,3-Dimethyl-4-sec-butylheptane
B)4-sec-Butyl-2,3-dimethylheptane
C)3,5,6-Trimethyl-4-propylheptane
D)2,3,5-Trimethyl-4-propylheptane

Question 24

What is the IUPAC name for the following compound?

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 25

What is the IUPAC name for the following compound?

A)2,3,5-Trimethylhexane
B)2,4,5-Triethylhexane
C)2,4-Diethyl-5-methylheptane
D)4-Ethyl-3,6-dimethyloctane

Question 26

What is the common name of the following alkyl group?

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

Question 27

What is the IUPAC name for the following compound?

A)1-sec-Butyl-4-isopropyl-2-methylcyclohexane
B)1-Isopropyl-3-methyl-4-sec-butylcyclohexane
C)4-Isopropyl-2-methyl-1-sec-butylcyclohexane
D)1-sec-Butyl-3-isopropyl-2-methylcyclohexane

Question 28

What is the IUPAC name for the following compound?

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 29

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

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 30

Which of the following is not a conformer of butane?

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

Question 31

What is the IUPAC name for the following compound?

A)1-Butyl-3-methylcyclohexane
B)1-sec-Butyl-3-methylcyclohexane
C)1-Methyl-3-sec-butylcyclohexane
D)1-sec-Butyl-3-methylhexane

Question 32

What is the IUPAC name for the following compound?

A)3,5-Diethyl-6-methylheptane
B)3,5-Diethyl-2-methylheptane
C)3-Ethyl-5-isopropylheptane
D)5-Ethyl-3-isopropylheptane

Question 33

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

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.

Question 34

Which of the following are gauche conformers?

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

Question 35

Which of the following statements about the conformations of acyclic alkanes is not true?

A)The staggered and eclipsed conformations are equally stable.
B)The staggered conformations are more stable than the eclipsed conformations.
C)An energy minimum and maximum occur every 60° as the conformation changes from staggered to eclipsed.
D)Conformations that are neither staggered nor eclipsed are intermediate in energy.

Question 36

Rank the following alkanes in order of increasing melting point,putting the alkane with the lowest melting point first.

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

Question 37

What is the common name of the following alkyl group?

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

Question 38

What is the IUPAC name for the following compound?

A)1,4-Dimethylcyclohexane
B)1,3-Dimethylcyclohexane
C)1,3-Dimethylcyclopentane
D)1,4-Dimethylcyclopentane

Question 39

What is the IUPAC name for the following compound?

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

Question 40

What is the IUPAC name for the following compound?

A)1-Butylcyclohexane
B)Cyclohexanebutane
C)1-Cyclohexylbutane
D)Butylcyclohexane

Question 41

Which of the following are anti conformers?

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

Question 42

What is the relation between the following pair of compounds?

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

Question 43

Which of the following is the highest energy conformer of 2,3-dimethylbutane?

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

Question 44

What are the products of the combustion of alkanes?

A)Carbon and hydrogen
B)Carbon and water
C)Carbon dioxide and hydrogen
D)Carbon dioxide and water

Question 45

Rank the conformers of butane in order of decreasing stability,putting the most stable first.

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

Question 46

Select the most stable conformer of cis-1,3-cyclohexanediol. .

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

Question 47

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

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

Question 48

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

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

Question 49

Which of the following chair conformations represents trans-1,4-dimethylcyclohexane?

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

Question 50

Which of the following cycloalkanes has the most angle strain?

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

Question 51

What is the IUPAC name of the following compound?

A)Pentane
B)2-Methylpentane
C)2-Methyl-3-ethylpentane
D)3-Ethyl-2-methylpentane

Question 52

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

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

Question 53

Which of the following conformers has the highest energy?

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

Question 54

Which of the following is the most stable conformation of the following compound?

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

Question 55

Rank the conformers of 1,2,4-trimethylcyclohexane in order of decreasing stability,putting the most stable first.

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

Question 56

What is the alternate chair conformation of the following compound?

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

Question 57

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

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

Question 58

Which of the following cycloalkanes has the least angle strain?

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

Question 59

Rank the following alkanes in order of increasing boiling point.

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

Question 60

Which of the following conformation is highest in energy?

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

Question 61

What is the IUPAC name for the following alkane?

A)3-isopropyl-6-methyloctane
B)3-isopropyl-3.7-methyloctane
C)3-ethyl-2,6-dimethyloctane
D)6-ethyl-3,7-dimethyloctane

Question 62

Which formula represents a cycloalkane with 5 carbons?

A)C₅H₈
B)C₅H₁₀
C)C₅H₁₂
D)C₅H₁₄

Question 63

Which formula represents a cycloalkane with 6 carbons?

A)C₆H₁₂
B)C₆H₁₄
C)C₆H₁₆
D)C₆H₁₈

Question 64

What is the IUPAC name for the following alkane?

A)2,5,6,7-tetramethyloctane
B)2,3,4,7-tetramethyloctane
C)2,5,6,7-tetramethylheptane
D)2,3,4,7-tetramethylheptane