University of New England

CHEM 1020

Chapter 2 -- Alkanes and Cycloalkanes

MULTIPLE CHOICE

1)What is the molecular formula of an alkane that has fourteen carbon atoms?

1. 1. C14H28
   2. C14H30
   3. C14H32
   4. C14H34
   5. C14H26

                                

 

2. What is the molecular formula of a cycloalkane that has six carbon atoms?
   1. C6H12
   2. C6H14
   3. C6H16
   4. C6H10
   5. C₆H₇

                                

 

3. What is the name of the alkane that has three carbon atoms?
   1. methane
   2. ethane
   3. propane
   4. butane
   5. isobutane

                                

 

4. The correct IUPAC name for the following molecule is:

 

 

 

 

1. 1. 6-ethyl-3,4,-dimethylheptane
   2. 2-ethyl-4,5-dimethylheptane
   3. 3,4,6-trimethyloctane
   4. 3,5,6-trimethyloctane
   5. none of these

                                

 

5. What is the common name for the following molecule?

 

 

 

1. 1. isobutyl bromide
   2. tert-butyl bromide
   3. butyl bromide
   4. sec-butyl bromide
   5. bromo-sec-butane

                                

 

6. The name of the alkyl group that contains three carbons is:
   1. methyl
   2. ethyl
   3. propyl
   4. isopropyl
   5. none of these

                                

 

7. Which of the following structures is 2-methylpentane?

 

A)

 

 

B)

 

 

 

 

C)

 

 

 

 

 

D)

 

 

 

 

E)

 

 

 

 

                                

 

8. The name of the alkyl group below is:

 

 

 

 

1. 1. ethyl
   2. propyl
   3. isopropyl
   4. butyl

1. 5. isobutyl

                                

 

9. What is the IUPAC name for the following compound?

 

 

 

 

 

1. 1. isohexyl bromide
   2. 3-bromo-4-methylpentane
   3. 1-bromopropylpropane
   4. 3-bromo-2-methylpentane
   5. 2-methyl-3-bromopentane

                                

 

10. The IUPAC name for the following molecule is:

 

 

 

 

1. 1. 2-chloro-3-ethyl-6,6-dimethylheptane
   2. 6-chloro-5-ethyl-2,2-dimethylheptane
   3. 6-chloro-2,2-dimethyl-5-ethylheptane
   4. 2,2-dimethyl-5-chloroethylheptane
   5. 6-chloro-5-ethyl-2-dimethylheptane

                                

 

11. 
    The IUPAC name for the following molecule is:
    1. 2-ethyl-4-methylpentane
    2. 4-methyl-2-methylpentane
    3. 2,4-dimethylhexane
    4. 1-isopropyl-2-methylbutane
    5. 2,4-methylhexane

                                

 

12. What is a correct name for the following molecule?

 

 

 

1. 1. 2,2-dichlorocyclopropane
   2. 1,1-dichlorocyclopentane
   3. 1,1-dichloropropane
   4. trans-1,1-dichlorocyclopropane
   5. 1,1-dichlorocyclopropane

                                

 

13. Trans-1-bromo-3-methylcyclobutane is represented by which structure below?

A)

 

 

 

B)

 

 

 

 

 

 

C)

 

D)

 

 

 

 

 

E)

 

 

 

 

 

 

                                

 

14. What is the correct name for the following cycloalkane?

 

 

 

 

1. 1. bromoethylcyclohexane
   2. trans-1-ethyl-3-bromocyclohexane
   3. cis-3-bromo-1-ethylhexane
   4. 1-bromo-3-ethylcyclohexane
   5. cis-1-bromo-3-ethylcyclohexane

                                

 

15. The correct IUPAC name for (CH₃)₂CHCH(CH₃)(CH₂)₃CH(CH₃)₂ is
    1. diisopropylpentane.
    2. 1,1,2,6,6-pentamethylhexane.
    3. 2,5-diisopropylpentane.
    4. 2,3,7-trimethyloctane.
    5. 1,4-diisopropylpentane.

 

                                

 

 

 

 

 

 

 

16. The correct IUPAC name for                                   is:

 

 

1. 1. 1,3,3-trimethylcyclobutane.
   2. cis-1,3,3-trimethylcyclobutane.
   3. trans-1,3,3-trimethylcyclobutane.
   4. 1,1,3-trimethylcyclobutane.
   5. 2,2,4-trimethylcyclobutane.

                                

 

17. The structural formula for 2,2,3-trimethylhexane is

 

A)

 

 

 

 

 

 

B)

 

 

 

 

C)

 

 

 

D)

 

 

 

 

 

 

E)

 

 

 

 

                                

 

18. Which of the following would exhibit hydrogen bonding?
    1. CH₃Cl
    2. CH₃OH
    3. CH₄
    4. CH₂Cl₂
    5. CH₃CH₃

                                

 

19. Which of the following alkanes would have the highest boiling point?
    1. pentane
    2. 2-methylbutane
    3. 2,2-dimethylpropane
    4. hexane
    5. 2-methylpentane

                                

 

20. What statement does NOT apply to the boiling points of alkanes?
    1. The boiling point increases as the length of the carbon chain increases.
    2. Straight chain alkanes have a higher boiling point than their branched isomers.
    3. Because they are nonpolar, alkanes have lower boiling points than other organic compounds of similar molar mass.
    4. The boiling points are affected by Van der Waals attractions.
    5. The boiling points are influenced by hydrogen bonding.

                                

 

21. Which cycloalkane has the highest boiling point?
    1. cyclopropane
    2. cyclobutane
    3. cyclopentane
    4. cyclohexane
    5. cyclooctane

                                

22. The boiling points of normal alkanes
    1. rise as the length of the carbon chain increases.
    2. rise as the length of the carbon chain decreases.
    3. are higher than the boiling points of branched alkanes with the same molecular formula.
    4. a and c
    5. b and c

                                

 

23. The most stable conformation of propane is:
    1. staggered
    2. chair
    3. planar
    4. eclipsed
    5. boat

                                

 

24. The least stable conformation of propane is:
    1. staggered
    2. chair
    3. planar
    4. eclipsed
    5. boat

                                

 

25. The preferred conformation of butane is given by which of the following Newman projection formulas?

 

A)

 

 

 

 

 

 

 

B)

 

 

 

 

 

 

C)

 

 

 

 

 

D)

 

 

 

E)

 

 

 

 

 

 

 

                                

 

26. The least stable conformation of butane is given by which of the following Newman projections?

 

A)

 

 

 

 

 

 

B)

 

 

 

C)

 

 

 

 

 

 

D)

 

 

 

 

 

E)

 

 

 

                                

 

27. The preferred conformation of cis-3-tert-butyl-1-methylcyclohexane is the one in which:
    1. the t-butyl group is axial and the methyl group is equatorial

1. 2. both groups are axial
   3. both groups are equatorial
   4. the methyl group is axial and the t-butyl group is equatorial
   5. molecule exists in a boat conformation

                                

 

28. The bond angle of a normal, tetrahedral, sp³ hybridized carbon is 109.5°. What is the C–C–C bond angle of cyclobutane?

A) 60°

B) 90°

C) 109.5°

D) 120°

E)   180°

                                

 

29. For the most stable conformation of cis-1,3-dimethylcyclohexane:
    1. both methyls will occupy the axial position
    2. both methyls will occupy the equatorial position
    3. one methyl will occupy the axial position and the other an equatorial position
    4. more than one answer is correct

                                

 

30. Which of the following pairs are examples of conformational isomerism?
    1. chair and boat forms of cyclohexane
    2. 1-iodopropane and 2-iodopropane
    3. sec-butyl chloride and butyl iodide
    4. cis and trans-1,2-dimethylcyclohexane
    5. all of these

                                

 

31. Consider this chair conformation:

 

 

 

 

 

 

 

When the ring flips,

1. 1. the bromine becomes axial and the methyls become equatorial.
   2. all three substituents become equatorial.
   3. the bromine becomes equatorial and the methyls become axial.
   4. the ring opens up.
   5. one methyl becomes axial, one becomes equatorial, and the bromine becomes equatorial.

                                

 

32. Consider this chair conformation:

 

 

 

 

 

1. 1. The methyl and bromine are cis and the chlorine and bromine are cis.
   2. The methyl and bromine are trans and the chlorine and bromine are cis.
   3. The methyl and chlorine are trans and the methyl and bromine are cis.
   4. The methyl and chlorine are trans and the methyl and bromine are trans.
   5. The methyl and chlorine are trans and the bromine and chlorine are cis.

                                

 

33. Cycloalkanes with                      or more carbons in the ring are nonplanar.
    1. 2
    2. 3
    3. 4
    4. 5
    5. 6

                                

 

34. 1-Bromopropane and 2-bromopropane are
    1. constitutional isomers.
    2. homologs.
    3. configurational isomers.
    4. conformational isomers.
    5. stereoisomers.

                                

 

35. The compounds represented by the structures below are:

 

 

 

 

1. 1. structural isomers.
   2. identical.
   3. cis-trans isomers.
   4. conformers.
   5. constitutional isomers.

                                

 

36. The compounds represented by the structures below are:

 

 

 

 

 

1. 1. structural isomers.
   2. different compounds.
   3. cis-trans isomers.
   4. conformers.
   5. constitutional isomers.

                                

 

37. The compounds represented by the structures below are:

 

 

 

 

 

1. 1. structural isomers.
   2. different compounds.
   3. cis-trans isomers.
   4. conformers.
   5. constitutional isomers.

                                

 

38. The compounds represented by the structures below are:

 

 

 

 

 

1. 1. constitutional isomers.
   2. identical.
   3. cis-trans isomers.
   4. conformers.
   5. different compounds (not isomers)..

                                

39. In the chlorination of methane, the propagation steps involve forming:
    1. H radicals
    2. methyl radicals
    3. chlorine radicals
    4. a, b, and c
    5. b and c

                                

 

40. How many monobromo products can be obtained from the bromination of cyclopentane?
    1. 1
    2. 2
    3. 3
    4. 4
    5. 5

                                

 

41. How many isomeric dichloro products can be obtained from the chlorination of cyclopropane?
    1. 1
    2. 2
    3. 3
    4. 4
    5. 5

                                

 

42. The number of possible monobromination products, including cis-trans isomers, of methylcyclopentane is
    1. 2
    2. 3
    3. 4
    4. 5
    5. 6

                                

 

43. The number of possible dibromination products of 2-methylpropane is
    1. 2
    2. 3
    3. 4
    4. 5
    5. 6

                                

 

44. The number of possible dichlorination products of propane is
    1. 2
    2. 3
    3. 4
    4. 5