1. Organic Chemistry, 7e by L. G. Wade, Jr.
Chapter 7 Structure and Synthesis of Alkenes
Christine Hermann
Radford University
Radford, VA
Copyright © 2010 Pearson Education, Inc.

2. 7.1 Describe the geometry around the carbon–carbon double bond.
a. Tetrahedral
b. Trigonal pyramidal
c. Trigonal planar
d. Bent
e. Linear

3. 7.1 Answer a. Tetrahedral b. Trigonal pyramidal c. Trigonal planar
d. Bent
e. Linear

4. 7.2 Give the formula for an alkene.
a. CnH2n-4
b. CnH2n-2
c. CnH2n
d. CnH2n+2
e. CnH2n+4

5. 7.2 Answer
a. CnH2n-4
b. CnH2n-2
c. CnH2n
d. CnH2n+2
e. CnH2n+4

6. 7.3 Name CH3CH=CHCH=CH2. a. 2,4-butadiene b. 1,3-butadiene
c. 2,4-pentadiene
d. 1,3-pentadiene
e. 1,4-pentadiene

7. 7.3 Answer a. 2,4-butadiene b. 1,3-butadiene c. 2,4-pentadiene
d. 1,3-pentadiene
e. 1,4-pentadiene

8. 7.4 Calculate the unsaturation number for C6H10BrCl.
d. 3

9. 7.4 Answer
a. 0
b. 1
c. 2
d. 3
U = 0.5 [2(6) + 2 – (12)] = 1

10. 7.5 Name . a. Trans-2-pentene b. Cis-2-pentene
c. Trans-3-methyl-2-pentene
d. Cis-3-methyl-2-pentene

11. 7.5 Answer a. Trans-2-pentene b. Cis-2-pentene
c. Trans-3-methyl-2-pentene
d. Cis-3-methyl-2-pentene
The longest chain is five carbons with numbering is left to right.

12. 7.6 Name . a. E-2-pentene b. Z-2-pentene c. E-3-methyl-2-pentene
d. Z-3-methyl-2-pentene
e. Z-2-methyl-2-pentene

13. 7.6 Answer a. E-2-pentene b. Z-2-pentene c. E-3-methyl-2-pentene
d. Z-3-methyl-2-pentene
e. Z-2-methyl-2-pentene
The longest chain is five carbons and the highest ranking groups are on opposite sides.

14. 7.7
a. CH3COOH
b. CH3CHO
c. CH3CH2OH
d. HOCH2CH2OH
e. CH3CH(OH)2

15. 7.7 Answer a. CH3COOH b. CH3CHO c. CH3CH2OH d. HOCH2CH2OH
e. CH3CH(OH)2
Ethylene oxide is formed first, followed by a ring opening to form ethylene glycol.

16. 7.8
a. ClCH2CH2Cl
b. ClCH=CHCl
c. CH2=CH2
d. CH2=CHCl

17. 7.8 Answer a. ClCH2CH2Cl b. ClCH=CHCl c. CH2=CH2 d. CH2=CHCl
Chlorine is added across the double bond, then HCl is lost.

18. 7.9
a. (CH3)2CHOH
b. CH3CH2CH2OH
c. HOCH2CH2CH2OH
d. CH3CH(OH)CH2OH

19. 7.9 Answer a. (CH3)2CHOH b. CH3CH2CH2OH c. HOCH2CH2CH2OH
d. CH3CH(OH)CH2OH
Water adds by Markovnikov’s orientation across the double bond.

20. 7.10
a. [CH2CH(CH3)]n
b. [CH2CH2]n
c. [CH2=CH(CH3)]n
d. [CH2=CH2]n

21. 7.10 Answer a. [CH2CH(CH3)]n b. [CH2CH2]n c. [CH2=CH(CH3)]n
d. [CH2=CH2]n

22. 7.11 Identify the product formed from the polymerization of tetrafluoroethylene.
a. Polypropylene
b. Poly(vinyl chloride), (PVC)
c. Polyethylene
d. Poly(tetrafluoroethylene), Teflon

23. 7.11 Answer a. Polypropylene b. Poly(vinyl chloride), (PVC)
c. Polyethylene
d. Poly(tetrafluoroethylene), Teflon
Teflon is formed from the polymerization of tetrafluoroethylene.

24. 7.12
a. CH3CCCH3
b. CH2=CHCH=CH2
c. CH3CH=CHCH3
d. CH3CH2CH2CH3

25. 7.12 Answer a. CH3CCCH3 b. CH2=CHCH=CH2 c. CH3CH=CHCH3
d. CH3CH2CH2CH3
Hydrogen adds across the double bond to form an alkane.

26. 7.13
a. (CH3)2C(Br)CH3
b. (CH3)2C=CHBr
c. (CH3)2C=CH2
d. (CH3)2CHCH3

27. 7.13 Answer a. (CH3)2C(Br)CH3 b. (CH3)2C=CHBr c. (CH3)2C=CH2
d. (CH3)2CHCH3
Both bromides are lost to form an alkene.

28. 7.14 Debromination of vicinal dibromides occurs by what mechanism?
a. SN1
b. SN2
c. E1
d. E2

29. 7.14 Answer
a. SN1
b. SN2
c. E1
d. E2
The debromination of vicinal dibromides occurs by an E2 mechanism.

30. 7.15
a. (CH3)2CHOSO3H
b. CH3CH=CH2
c. (CH3)2C=O
d. CH3CH2COOH

31. 7.15 Answer a. (CH3)2CHOSO3H b. CH3CH=CH2 c. (CH3)2C=O d. CH3CH2COOH
Acid dehydrates alcohols to form alkenes.

32. 7.16 Dehydration of alcohols occurs by what mechanism?
a. SN1
b. SN2
c. E1
d. E2

33. 7.16 Answer
a. SN1
b. SN2
c. E1
d. E2
The dehydration of alcohols occurs by an E1 mechanism.

34. 7.17 Give the products from the catalytic cracking of alkanes.
a. Alkanes
b. Alkenes
c. Alkynes
d. Alkanes + alkenes
e. Alkanes + alkynes

35. 7.17 Answer a. Alkanes b. Alkenes c. Alkynes d. Alkanes + alkenes
e. Alkanes + alkynes

36. 7.18 Give the products from the dehydrogenation of alkanes.
a. Alkanes
b. Alkenes
c. Alkynes
d. Alkanes + alkenes
e. Alkanes + alkynes

37. 7.18 Answer a. Alkanes b. Alkenes c. Alkynes d. Alkanes + alkenes
e. Alkanes + alkynes

38. 7.19 a. (CH3)3CO-, (CH3)3COH b. CH3CH2O-, CH3CH2OH c. NaI, acetone
d. H2, Pd

39. 7.19 Answer a. (CH3)3CO-, (CH3)3COH b. CH3CH2O-, CH3CH2OH
c. NaI, acetone
d. H2, Pd
The Hofmann product (least substituted) is favored with a bulky base.

40. 7.20
a. Pt, 500o C
b. H2, Pt
c. H2SO4, 150o C
d. NaI, acetone
e. NaOH

41. 7.20 Answer a. Pt, 500o C b. H2, Pt c. H2SO4, 150o C d. NaI, acetone
e. NaOH
Dehydrogenation occurs with a metal catalyst and heat.