Chapter 12 Alkanes Test Questions & Answers

General, Organic and Biological Chemistry, 4e (Smith)

Chapter 12 Alkanes

1) How many hydrogen atoms are present in a cyclic alkane with six (6) carbon atoms?

A) 6

B) 8

C) 10

D) 12

E) 14

2) How many hydrogen atoms are present in an acyclic alkane with five (5) carbon atoms?

A) 5

B) 7

C) 9

D) 10

E) 12

3) Which formula represents an acyclic alkane?

A) C10H18

B) C9H18

C) C12H26

D) C10H20

E) C12H28

4) Which formula represents a cyclic alkane?

A) C10H18

B) C10H22

C) C9H20

D) C10H20

E) C11H20

5) Which of the following compounds is identical to the one shown below? 

A)

B)

C)

D)

6) Which of the following is a constitutional isomer of the compound shown below?

A)

B)

C)

D)

E) More than one of the molecules is a constitutional isomer of the original molecule.

7) Constitutional isomers differ in the ________.

A) identities of the atoms in the molecule

B) number of hydrogen atoms in the molecule

C) way the atoms are connected to each other

D) molecular formula used to describe them

8) Which molecule is a constitutional isomer of the compound (CH3)2CH(CH2)2CH3?

A) CH3CH2CH2CH(CH3)2

B)

C)

D)

9) Which molecular formula has the largest number of constitutional isomers?

A) C5H12

B) C2H6

C) C6H14

D) All of the molecular formulas above have the same number of constitutional isomers.

10) Which of the following pairs of compounds are constitutional isomers?

A)

B)

C)

D)

11) What is the IUPAC name of CH3CH2CH2CH3?

A) Butane

B) Methane

C) Propane

D) Pentane

12) What is the IUPAC name of CH3CH2CH2CH2CH2CH3?

A) Butane

B) Hexane

C) Propane

D) Pentane

E) Heptane

13) How many primary carbon atoms are in the straight-chain alkane with the formula C3H8?

A) 0

B) 1

C) 2

D) 3

E) 4

14) How many secondary carbons are in the straight-chain alkane with the formula C4H10?

A) 0

B) 1

C) 2

D) 3

E) 4

15) What is the classification of each labeled carbon atom in the structure below?

A) C1 is a secondary carbon and C2 is a primary carbon.

B) C1 is a tertiary carbon and C2 is a secondary carbon.

C) C1 is a secondary carbon and C2 is a tertiary carbon.

D) C1 is a primary carbon and C2 is a tertiary carbon.

16) Which structure depicts an alkane of molecular formula C6H12 that has two 1° carbons and two 3° carbons?

A)

B) CH3CH2CH2CH2CH2CH3

C)

D)

17) What is the IUPAC name of this compound?

A) 4-propylhexane

B) 3-ethyl-2-methylhexane

C) 2-methyl-3-ethylhexane

D) 4-ethyl-5-methylheptane

18) What is the IUPAC name of this compound? 

A) 4-isopentylnonane

B) 3-ethyl-4-propylnonane

C) 3,3-dimethyl-4-propylnonane

D) 3,3-dimethyl-4-butylnonane

19) What is the IUPAC name of this compound?

A) Heptane

B) 1,1,3,3-tetramethylpropane

C) 2,4-dimethylpentane

D) 1,5-dimethylpentane

20) What is the IUPAC name of this compound?

A) 3-ethyl-5-methyldecane

B) 3-ethyl-2-pentylhexane

C) 3-ethyl-5-pentylhexane

D) 8-ethyl-6-methyldecane

21) What is the IUPAC name of this compound?

A) Ethyl-methyl-cyclopropane

B) Ethyl-2-methylcyclobutane

C) 1-ethyl-2-methylcyclobutane

D) 1-ethyl-2-methylcyclopropane

E) Ethyl-2-methylcyclotriane

22) What is the structure of 2-methylhexane?

A) (CH3)2CHCH2CH2CH3

B) (CH3)2CHCH2CH2CH2CH3

C) (CH3)3CCH2CH2CH2CH3

D)

23) What is the structure of 4 propyloctane?

A)

B)

C)

D)

24) What is the structure of butylcyclopentane?

A)

B)

C)

D)

25) What is the structure of 1-ethyl-2-methylcyclohexane?

A)

B)

C)

D)

26) Which has the highest boiling point?

A) Natural gas

B) Lubricating oil

C) Gasoline

D) Kerosene

E) Fuel oil

27) Which alkane has the lowest boiling point?

A) Octane

B) Butane

C) Ethane

D) Hexane

E) Propane

28) Which balanced chemical equation represents the incomplete combustion of a hydrocarbon?

A) CH3CH2CH3 + 5 O2 → 3 CO2 + 4 H2O

B) 2 CH3CH2CH3 + 7 O2 → 6 CO + 8 H2O

C) C36H74 + 36 O2 → 36 CO + 37 H2O

D) C26H50 + 33 O2 → 16 CO2 + 10 CO + 25 H2O

29) How many quaternary carbons are in this molecule?

A) 0

B) 1

C) 4

D) 5

30) How many secondary carbons are in the molecule (CH3)2CH(CH2)2CH3?

A) 0

B) 1

C) 2

D) 3

E) 4

31) How many tertiary carbons are in the molecule (CH3)2CH(CH2)2CH3?

A) 0

B) 1

C) 2

D) 3

E) 4

32) What is the classification of each labeled carbon atom in this structure?

A) C1 is a 1°, C2 is 2°, C3 is a 3°, and C4 is 4°.

B) C1 is a 2°, C2 is 3°, C3 is a 3°, and C4 is 4°.

C) C1 is a 1°, C2 is 2°, C3 is a 3°, and C4 is 1°.

D) C1 is a 2°, C2 is 3°, C3 is a 2°, and C4 is 3°.

33) What is the classification of each labeled carbon atom in this structure?

A) C1 is a 1°, C2 is 2°, and C3 is a 3°.

B) C1 is a 2°, C2 is 1°, and C3 is a 3°.

C) C1 is a 3°, C2 is 2°, and C3 is a 1°.

D) C1 is a 3°, C2 is 1°, and C3 is a 2°.

34) Which name is not a valid IUPAC name for an alkane?

A) 2,3,4-trimethylhexane

B) 1-butyl-2-ethylcyclopentane

C) 1-ethyl-2-butylpentane

D) 5-butyl-2-methylnonane

35) Which name represents a valid IUPAC name for an alkane?

A) 1,4-diethylheptane

B) 4,4-diethyl-2,3,4-trimethylpentane

C) 4,4-diethyl-2,3,4-trimethylcycloheptane

D) 4,4-diethyl-2,3-dimethylheptane

E) More than one of the names is a valid IUPAC name for an alkane.

36) Which compound has the lowest melting point?

A) CH3CH2CH2CH2CH3

B) CH3CH2CH2CH2CH2CH2CH2CH3

C) CH3CH2CH2CH2CH2CH3

D) CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3

37) What is the IUPAC name of this molecule?

A) 2,4-dimethyl-2-ethylhexane

B) 2-ethyl-2,4-dimethylhexane

C) 3,3,5-trimethylheptane

D) 5-ethyl-3,5-dimethylhexane

38) Which compound is identical to this molecule?

A) (CH3)2CHCH2CH2CH3

B) CH3(CH2)4CH3

C)

D)

E) More than one molecule is identical to the original molecule.

39) Which compound is identical to this molecule?

A)

B)

C)

D)

E) More than one molecule is identical to the original molecule.

40) Branching in an alkane chain decreases surface area. With this in mind, which of the following alkanes has the highest boiling point?

A) (CH3)2CHCH2CH2CH2CH2CH3

B) (CH3)2CHCH2CH2CH(CH3)2

C) CH3CH2CH2CH2CH2CH2CH2CH3

D) (CH3)3CC(CH3)3

41) Which is NOT a property associated with tetradecane, a 14-carbon straight chain alkane?

A) Strong hydrogen bonds

B) Low water solubility

C) Density less than water

D) Flammable liquid

42) What is the classification of the carbon atom that bonded to the –OH group in menthol?

A) Primary

B) Secondary

C) Tertiary

D) Quaternary

43) What is the classification of C1 on the molecule below?

A) Primary

B) Secondary

C) Tertiary

D) Quaternary

44) Decane has the structure: CH3(CH2)9CH3. What does the prefix "dec-" specifically indicate about the structure of this compound?

A) It contains a straight chain of carbons.

B) It contains 10 carbons in a continuous chain.

C) It is an alkane.

D) It is a saturated hydrocarbon.

45) Asphalt is a mixture of high molecular weight hydrocarbons. Which solvent would be best for removing asphalt from a newly paved road off the bottom of a pair of shoes?

A) Water

B) Octane

C) Methanol, CH3OH

D) NaCl(aq)

46) Which types of compounds are saturated hydrocarbons?

A) Alkenes

B) Aromatic hydrocarbons

C) Alkanes

D) Alkynes

E) All of the hydrocarbons are unsaturated hydrocarbons.

47) What alkyl halide is formed when CH3CH3 is heated with bromine, Br2?

A) C2Br6

B) CH2=CH2

C) CH3CH2OH

D) CH3CH2Br

48) What type of compound is formed with an alkane reacts with light and chlorine, Cl2?

A) Alkene

B) Alkyl halide

C) Alkyne

D) Cycloalkane

49) The molecules below are constitutional isomers.

50) The compounds below are constitutional isomers.

51) The compounds below are constitutional isomers.

52) The compounds below are constitutional isomers.

53) The molecules below are constitutional isomers.

54) The compounds shown below are related as constitutional isomers.

55) The products of the complete combustion of any hydrocarbon are CO2 + H2O, regardless of the identity of the starting material.

56) All organic molecules must have at least one primary carbon atom.

57) CO2 is a greenhouse gas.

58) The combustion of alkanes and other hydrocarbons obtained from fossil fuels adds a tremendous amount of CO2 to the atmosphere each year.

59) Shark liver oil is approximately 14% pristane (C19H40). Pristane is an acyclic alkane.

60) A branched alkane and a cycloalkane with the same number of carbons have the same number of hydrogen atoms in their chemical formulas.

61) Alkanes containing only secondary carbon atoms do not exist.

62) The IUPAC name of the molecule (CH3)2CH(CH2)2CH3 is 2-methylhexane.

63) If a cyclic alkane has 28 hydrogens and a single ring, it must have 13 carbon atoms.

64) 5-ethyl-2-methylhexane is a valid IUPAC name for an alkane.

65) 5-methyl-2-butylnonane is a valid IUPAC name for an alkane.

66) 5-methyl-5-propylnonane is a valid IUPAC name for an alkane.

67) 5,5-dimethyl-5-propylnonane is a valid IUPAC name for an alkane.

68) 1,1-dimethylcyclohexane is a valid IUPAC name for an alkane.

69) Pentane has a higher boiling point than 2,2-dimethylpropane.

70) The molecular formula for an alkane with 12 carbon atoms and two rings is C12H24.

71) The two structures below represent the same compound.

72) The two structures below represent the same compound.

73) C2H6 has a higher boiling point than the compound below.

74) The IUPAC name of the molecule below is butylcyclopentane.

75) The IUPAC name of the molecule below is propylcyclobutane.

76) Acyclic alkanes with four or more carbon atoms have constitutional isomers.

77) Oxidation results in a decrease in the number of C—O bonds and an increase in the number of C—H bonds.

78) Natural gas is composed primarily of propane.

79) Cyclic alkanes are planar molecules containing one or more rings of carbon.

80) The molecule below contains 1°, 2°, and 3° carbon atoms, but no 4° carbon atoms.

81) The molecule below contains 1°, 2°, and 4° carbon atoms, but no 3° carbon atoms.

82) The IUPAC name for the molecule below is 2,3-diethyl-2-methylpentane.

83) The compound below is an example of a saturated hydrocarbon.

84) The compound below is an example of a saturated hydrocarbon.

85) An acyclic alkane has the general molecular formula CnH2n-2, where n is the number of carbon atoms it contains.

86) A cyclic alkane has the general molecular formula CnH2n, where n is the number of carbon atoms it contains.

87) A branched-chain alkane with five carbon atoms has the same number of hydrogen atoms that a straight-chain alkane with five carbon atoms has.

88) Combustion is an example of an oxidation–reduction reaction.

89) Octane is a saturated hydrocarbon with eight carbons attached in a continuous chain.

90) There are ________ constitutional isomers for the five-carbon alkane, each having molecular formula C5H12.

91) A four-carbon substituent bonded to a long carbon chain is called ________.

92) The IUPAC name of an organic compound can be long and complex. As a result, most drugs have three names: ________, ________, and ________.

93) Alkyl groups are named by changing the -ane ending of the parent alkane to the suffix ________.

94) Cycloalkanes with 14 to 18 carbon atoms occur in musk, extracted from deer of the family Moschidae. If one of these cycloalkanes has one ring and 17 carbon atoms, it has ________ hydrogen atoms.

95) The molecule below has ________ primary carbon atoms, ________ secondary carbon atoms, ________ tertiary carbon atoms, and ________ quaternary carbon atoms.

A) 4, 8, 1, 1

B) 4, 7, 2, 0

C) 5, 7, 2, 0

D) 5, 7, 1, 1

E) 5, 8. 2. 0

96) The molecule below has ________ primary carbon atoms, ________ secondary carbon atoms, ________ tertiary carbon atoms, and ________ quaternary carbon atoms.

97) The IUPAC name of the compound below is ________.

98) The IUPAC name of the compound below is ________.

99) The products of the incomplete combustion of an alkane are ________ and water.

100) Two different compounds with the same molecular formulas that differ in the way the atoms are connected to each other are called ________.

101) The name of the compound below is ________.

102) The name of the compound below is ________.

103) There are ________ carbons in the longest continuous chain of carbons in the molecule below.

A) 6 (six)

B) 7 (seven)

C) 8 (eight)

D) 9 (nine)

E) 10 (ten)

104) There are ________ carbons in the longest continuous chain of carbons in the molecule below.