1. Chemistry 121 Winter
Introduction to Organic Chemistry and Biochemistry
Instructor Dr. Upali Siriwardane (Ph.D. Ohio State)
Office: 311 Carson Taylor Hall ; Phone: ;
Contact me trough if you have questions
Online Tests on Following days
December 16, 2016: Test 1 (Chapters 12-13)
January 23, 2017 : Test 2 (Chapters 14-16)
February 10, 2017 : Test 3 (Chapters 17-19)
February 22, 2017 : Test 4 (Chapters 20-22)
February 23, 2017: Make Up Exam: Chapters 12-22)

2. GHW Questions
GHW#3
CHEM 121 Winter 16

3. Chapter 12. Saturated Hydrocarbons
12.1 Organic and Inorganic Compounds, 341
12.2 Bonding Characteristics of the Carbon Atom, 342
12.3 Hydrocarbons and Hydrocarbon Derivatives, 342
12.4 Alkanes: Acyclic Saturated Hydrocarbons, 343
12.5 Structural Formulas, 344
12.6 Alkane Isomerism, 346
12.7 Conformations of Alkanes, 348
12.8 IUPAC Nomenclature for Alkanes, 350
12.9 Line-Angle Structural Formulas for Alkanes, 356
12.10 Classification of Carbon Atoms, 358
12.11 Branched-Chain Alkyl Groups, 359
12.12 Cycloalkanes, 361
12.13 IUPAC Nomenclature for Cycloalkanes, 362
12.14 Isomerism in Cycloalkanes, 363
12.15 Sources of Alkanes and Cycloalkanes, 365
12.16 Physical Properties of Alkanes and Cycloalkanes, 367
12.17 Chemical Properties of Alkanes and Cycloalkanes, 368
12.18 Halogenated Alkanes and Cycloalkanes, 371
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4. Chapter 13. Unsaturated Hydrocarbons
13.2 Characteristics of Alkenes and Cycloalkenes, 385
13.3 IUPAC Nomenclature for Alkenes and Cycloalkenes, 386
13.4 Line-Angle Structural Formulas for Alkenes, 389
13.5 Constitutional Isomerism in Alkenes, 390
13.6 Cis-Trans Isomerism in Alkenes, 391
13.7 Naturally Occurring Alkenes, 394
13.8 Physical Properties of Alkenes and Cycloalkenes, 396
13.9 Chemical Reactions of Alkenes, 396
13.10 Polymerization of Alkenes: Addition Polymers, 402
13.11 Alkynes, 406
13.12 Aromatic Hydrocarbons, 408
13.13 Names for Aromatic Hydrocarbons, 410
13.14 Aromatic Hydrocarbons: Physical Properties and Sources, 413
13.15 Chemical Reactions of Aromatic Hydrocarbons, 413
13.16 Fused-Ring Aromatic Hydrocarbons, 414
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5. Isomerism Skeleton Position Functional group geometric conformational
Isomers - different compounds having the same molecular formula but different structural formulas
There are two type of Isomers:
Constitutional isomerism: Different connections among atoms in the
Skeleton
Position
Functional group
Stereoisomerism: Same connectivity among atoms, but these atoms differ in spatial orientation
geometric
conformational
optical
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6. Constitutional Isomers
Skeletal (Chp. 12)
Functional (Chp. 14)
Positional (Chp. 12)
Stereoisomers
Geometric (Chp. 13)
Conformational (Chp.12)
Enantiomers (Optical) (Chp. 16)
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7. 1. Write the name of names and units of unsaturation for the hydrocarbons (alkane, alkene, alkyne and arene) with following general formula.
CnH2n+2 CnH2n CnH2n CnHn
Name a) ______ b) ____ c) ____ d) ___
Unit of unsat. a) ______ b) ____ c) ____ d) ___
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8. 2. Draw all constitutional isomers of butane: C4H10.
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9. 3. Names of following cycloalknes:
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10. 4. Complete the following reactions of alkanes.
a) Combustion:
C5H12(g) O2(g)  ___CO2(g) + ___H2O(g)
ii) C4H10(g) + ___ O2(g)  ___CO2(g) + ___H2O(g)
b) Halogenations:
(substitution reaction to form alkyl halides)
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11. Unsaturated hydrocarbons
Hydrocarbons with carbon-carbon double bonds and triple bonds
double bonds: alkenes
triple bonds: alkynes
three alternating double bond in 6 carbon ring: aromatics
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12. Chapter 13 – Unsaturated Hydrocarbons
I. Alkenes and Alkynes
Alkenes
Alkynes

13. Chapter 13 – Unsaturated Hydrocarbons
III. Aromatic Compounds

14. Unsaturated Hydrocarbons:
Alkenes Alkynes Arenes
ethene ethyne benzene
C2H4 C2H2 C6H6
CnH2n CnH2n CnHn
unsaturated unsaturated Aromatic
alkene alkyne Arene
Chapters 13 Chapters Chapter 13
CHEM 121 Winter 16

15. Units of Unsaturation:
Alkenes Alkynes Arenes
ethene ethyne benzene
C2H4 C2H2 C6H6
CnH2n CnH2n CnHn
Units of Unsaturation
CnH2n+2 CnH2n+2 CnH2n+2
(6-4)/2 =1 (6-2)/2 =2 (14-6)/2 =4
one double = one triple  three double =
1 ring
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16. Nomenclature of Alkenes: Common Names
Some alkenes, particularly low-molecular-weight ones, are known almost exclusively by their common names
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17. Nomenclature (IUPAC) of Alkenes and Alkynes
HOW TO Name an Alkene or Alkyne
Find the longest chain that contains both
C atoms of the double or triple bond.
Step [1]
4 C’s in longest chain
6 C’s in longest chain
butane ----> butene
hexane ----> hexyne

18. Example of IUPAC Nomenclature of Alkenes Cycloalkanes
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19. Nomenclature of Alkenes and Alkynes
HOW TO Name an Alkene or Alkyne
Number the carbon chain from the end that
gives the multiple bond the lower number.
Step [2]
1-butene
2-hexyne

20. IUPAC Nomenclature of Alkynes
use the infix -yn- to show the presence of a carbon-carbon triple bond
number the parent chain to give the 1st carbon of the triple bond the lower number
follow IUPAC rules for numbering and naming substituents
CHEM 121 Winter 16

21. Unsaturated Hydrocarbons in Use
Acetylene: Welding
Beta-carotene is in carrots
sex pheromones in insect control
involves luring insect into a trap.
Ethene is the hormone
that causes tomatoes to ripen.
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22. Naturally Occurring Alkenes Cis-Trans Isomerism
vitamin A has five double bonds
four of the five can show cis-trans isomerism
vitamin A is the all-trans isomer
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23. Naturally Occurring Alkenes: The Terpenes
Terpene: a compound whose carbon skeleton can be divided into two or more units identical with the carbon skeleton of isoprene
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24. Terpenes with isoprene units
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25. Terpenes: Polymers of Isoprene
myrcene, C10H16, a component of bayberry wax and oils of bay and verbena
menthol, from peppermint
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26. Terpenes Vitamin A (retinol)
the four isoprene units in vitamin A are shown in red
they are linked head to tail, and cross linked at one point (the blue bond) to give the six-membered ring
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27. 5) How many isoprene units a in the following natural product?
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28. 6) Give common name or/and IUPAC names of following compounds a) b) c)
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29. Cis and trans Geometrical isomers of alkenes
Two groups are said to be located cis to each other if they lie on the same side of a plane with respect to the double bond.
If they are on opposite sides, their relative position is described as trans.
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30. Isomerism in Unsaturated Hydrocarbons
II. Stereoisomers Geometrical
2-butene
A. Cis/trans isomers

31. Cis-Trans Isomerism Dienes, trienes, and polyenes
for an alkene with n carbon-carbon double bonds, each of which can show cis-trans isomerism, 2n cis-trans isomers are possible
consider 2,4-heptadiene; it has four cis-trans isomers, two of which are drawn here
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32. 6) Give common name or/and IUPAC names of following compounds e) f)
h) i)
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33. Physical Properties Alkenes and alkynes are nonpolar compounds
the only attractive forces between their molecules are dispersion forces
Their physical properties are similar to those of alkanes of similar carbon skeletons
those that are liquid at room temperature are less dense than water (1.0 g/m L)
they dissolve in each other and in nonpolar organic solvents
they are insoluble in water
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34. Summary of Physical State of Unsaturated Hydrocarbons
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35. Reactions of Unsaturated Hydrocarbons
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36. Chemical Reactions of Alkenes
1) Combustion: Alkenes are very flammable and the combustion products are carbon dioxide and water.
2) Addition Reactions: Atoms or group of atoms are added to each a carbon atom of a multiple bond. Two different reactants are involved.
a) Symmetric Addition Reactions:
Hydrogenation reaction: hydrogenation a hydrogen atom is added to each carbon atom of a double bond. Catalyst (usually Ni or Pt) is needed.
Halogenation reaction: In alkene halogenation a halogen atom is added to each carbon atom of a double bond. No catalyst is needed.
b) Asymmetric Addition Reactions: both reactants (H-X (X= Cl, OH)) and the alkene need to be asymmetric
c) Polymerization of Alkenes: Addition Polymers
Polymers are macromolecules in which small units (monomers) are repeated again and again.
CHEM 121 Winter 16

37. Reactions of Unsaturated Hydrocarbons
III. Reactions of Alkenes
Addition Reactions
1. Hydrogenation

38. Chapter 13 – Unsaturated Hydrocarbons
2. Halogenation
3. Hydrohalogenation

39. Addition Reactions of Alkenes
4. Markovnikov’s Rule
C2 is bonded to 1 H
C1 is bonded to 2 H’s
C1 has more H’s, so it will bond to the H from HCl.
2-Chloropropane is the only product formed.

40. Markovnikov’s Rule
When an unsymmetrical molecule HQ (e.g., H-Cl, H-OH, H-F) reacts with an unsymmetrical alkene, the hydrogen atom from the HQ becomes attached to the unsaturated carbon atom that already has the most hydrogen atoms
CHEM 121 Winter 16

41. Addition Reactions of Alkenes
5. Hydration
this C has no H’s
CH3
CH3
H2SO4 OH + H OH H H H
this C has 1 H
only product

42. Addition Reactions of Alkenes

43. Hydration Addition of water to the double bond. Textbook page86.
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44. 7) Complete the reactions of following alkenes
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45. 7) Complete the reactions of following alkenes
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46. Polymerization of Alkenes
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47. CHEM 121 Winter 16

48. Aromatic hydrocarbons
Aromatic hydrocarbons - organic compounds that had aromas and had different chemical properties from alkane
Benzene is the parent compound for the aromatic hydrocarbons. Textbook, page90.
Consider benzene. C6H6
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49. Chapter 13 – Unsaturated Hydrocarbons
III. Aromatic Compounds

50. Unsaturated Hydrocarbons cont’d
Space-filling and ball-and-stick models for the structure of benzene.
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51. Resonance Structures of Benzene
Resonance structures or contributing structures = when two or more structure can be drawn for a compound.
In this case, the real structure is something between the proposed structures.
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52. Nomenclature of Aromatic Compounds
1. One substituent

53. Chapter 13 – Unsaturated Hydrocarbons
2. Disubstituted Benzenes

54. 3. Polysubstituted Benzenes
ortho-xylene
o-xylene
1,2-dimethylbenzene
meta-xylene
m-xylene
1,3-dimethylbenzene
para-xylene
p-xylene
1,4-dimethylbenzene
3. Polysubstituted Benzenes
4-chloro-1-ethyl-2-propylbenzene

55. 2,5-dichloroaniline
Some common drugs that contain benzene
rings are:

56. Naming Aromatic Hydroarbons.
Monosubstituted benzenes:
Ar-CH2CH3 ethylbenzene
Ar-CH2-CH2-CH2-CH3 butylbenzene
Ar-CH3 (methylbenzene) toluene
Ar-X (halobenzene) bromobenzene,
Ar-NO2 nitrobenzene
Ar-SO3H benzenesulfonic acid
Ar-NH2 a nitrile substituent X
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57. CHEM 121 Winter 16

58. Nomenclature Disubstituted benzenes
locate substituents by numbering or
use the locators ortho (1,2-), meta (1,3-), and para (1,4-)
Where one group imparts a special name, name the compound as a derivative of that molecule
CHEM 121 Winter 16

59. Nomenclature Polysubstituted benzenes
with three or more substituents, number the atoms of the ring
if one group imparts a special name, it becomes the parent name
if no group imparts a special name, number to give the smallest set of numbers, and then list alphabetically
CHEM 121 Winter 16

60. Disubstituted benzenes:
2,6-dibromotoluene
p-diethylbenzene
3,5-dinitrotoluene
p-cholonitrobenzene
o-nitrobenzenesulfonic acid
4-benzyl-1-octene
m-cyanotoluene
CHEM 121 Winter 16

61. 8) Match the following names of aromatic hydrocarbons (arenes)
to following structures: Anisole, Aniline, Phenol, Benzoic acid, Toluene,
Nitrobenzene. Complete the reactions of following alkenes
_________ _________ _________ _________ _________ _________
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62. 9. Give the names of the following disubstituted aromatic hydrocarbons.
_________ _________ _________ _________
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63. Reactions of Aromatic Hydrocarbons
No Addition Reactions
Show substitution Reactions
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64. 10) Complete the following chemical reactions of aromatic hydrocarbons.
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