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? C14H28 C14H30 C14H32 C14H34 C14H26                                    What is the molecular formula of a cycloalkane that has six carbon atoms? C6H12 C6H14 C6H16 C6H10 C6H7                                    What is the name of the alkane that has three carbon atoms? methane ethane propane butane isobutane                                    The correct IUPAC name for the following molecule is:             6-ethyl-3,4,-dimethylheptane 2-ethyl-4,5-dimethylheptane 3,4,6-trimethyloctane 3,5,6-trimethyloctane none of these                                    What is the common name for the following molecule?         isobutyl bromide tert-butyl bromide butyl bromide sec-butyl bromide bromo-sec-butane                                    The name of the alkyl group that contains three carbons is: methyl ethyl propyl isopropyl none of these                                    Which of the following structures is 2-methylpentane?   A)     B)         C)           D)         E)                                            The name of the alkyl group below is:             ethyl propyl isopropyl butyl   isobutyl                                    What is the IUPAC name for the following compound?               isohexyl bromide 3-bromo-4-methylpentane 1-bromopropylpropane 3-bromo-2-methylpentane 2-methyl-3-bromopentane                                    The IUPAC name for the following molecule is:             2-chloro-3-ethyl-6,6-dimethylheptane 6-chloro-5-ethyl-2,2-dimethylheptane 6-chloro-2,2-dimethyl-5-ethylheptane 2,2-dimethyl-5-chloroethylheptane 6-chloro-5-ethyl-2-dimethylheptane                                        The IUPAC name for the following molecule is: 2-ethyl-4-methylpentane 4-methyl-2-methylpentane 2,4-dimethylhexane 1-isopropyl-2-methylbutane 2,4-methylhexane                                    What is a correct name for the following molecule?         2,2-dichlorocyclopropane 1,1-dichlorocyclopentane 1,1-dichloropropane trans-1,1-dichlorocyclopropane 1,1-dichlorocyclopropane                                    Trans-1-bromo-3-methylcyclobutane is represented by which structure below? A)       B)                 C)   D)           E)                                                What is the correct name for the following cycloalkane?           bromoethylcyclohexane trans-1-ethyl-3-bromocyclohexane cis-3-bromo-1-ethylhexane 1-bromo-3-ethylcyclohexane cis-1-bromo-3-ethylcyclohexane                                    The correct IUPAC name for (CH3)2CHCH(CH3)(CH2)3CH(CH3)2 is diisopropylpentane

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?

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)

D)

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

C)

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?

C)

D)

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

B)

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