1. Chemistry 30 – Organic Chemistry – Part 1
To accompany
Inquiry into Chemistry
PowerPoint Presentation prepared by Robert Schultz

2. Organic Chemistry – Preparation – VSEPR
Recall VSEPR Theory (valence shell electron pair repulson theory) from Chemistry 20
Organic chemistry will involve 3 particular groupings:
0 lone pairs, 4 bonding pairs - tetrahedral
H C H H ••

3. Organic Chemistry – Preparation - VSEPR
0 lone pairs, 3 bonding pairs – trigonal planar
0 lone pairs, 2 bonding pairs - linear
H C H O ••
O C O ••

4. Organic Chemistry - Preparation
Recall polarity of covalent bonds from Chemistry 20: 2 particular polar bonds important in organic chemistry
C – H bonds are virtually non-polar
O — H
C = O

5. Organic Chemistry – Preparation – Intermolecular Forces
London Dispersion Forces – all moleculars – temporary dipoles – affected by total # of e- and shape
Dipole-dipole Forces – polar moleculars
Hydrogen Bonding (H covalently bonded to F, O, or N)
affect melting point, boiling point, and solubility

6. Organic Chemistry – 14.1 - Introduction
Organic compounds – originally defined to be compounds from living or once-living organisms
Wohler, 1828, synthesized urea (an organic compound) from inorganic chemicals
Today organic compounds defined to be molecular compounds of carbon – exception: oxides of carbon – CO, CO2

7. Organic Chemistry – 14.1 - Introduction
Most existing compounds are organic!
Special things about carbon that allow it to form so many different compounds:
• 4 bonding electrons
• ability to form single, double, triple bonds with itself
• ability to bond with itself in many different configurations

8. Organic Chemistry – 14.1 - Introduction
Classification:
organic compounds
hydrocarbons C and H only
hydrocarbon derivatives C and H along with O, N, and/or halogen atoms
aliphatics without
aromatics with
alkynes – 1 triple bond between C’s – CnH2n-2
alkenes – 1 double bond between C’s – CnH2n
alkanes – all single bonds – CnH2n+2

9. Organic Chemistry – 14.2 - Hydrocarbons
Alkanes - saturated hydrocarbons
Term saturated used because alkanes have the maximum number of hydrogens
General formula: CnH2n+2
butane
first 4 alkanes
methane
ethane
propane

10. Organic Chemistry – 14.2 - Hydrocarbons
The unbranched alkanes are a homologous series because they differ by the number of CH2 units in each
Alkanes are tetrahedral around each carbon

11. Organic Chemistry – 14.2 - Hydrocarbons
Since carbons and hydrogens can join up in so many ways, structural formulas are used
Different types of structural formulas:
we won’t use this type 3 3 2 3

12. Organic Chemistry – 14.2 – Hydrocarbons: Alkanes
Nomenclature of alkanes:
You must learn the following prefixes:
# of C’s
prefix 1
meth 2
eth 3
prop 4
but 5
pent 6
hex 7
hept 8
oct 9
non 10
dec

13. Organic Chemistry – 14.2 – Hydrocarbons: Alkanes
Start naming by finding the longest continuous chain of carbon atoms. Name the long chain using its prefix with an ane ending.
Identify branches, and name using their prefix with a yl ending.
Number the longest continuous chain from the end closest to the branching and use the numbers like addresses for the branches.

14. Organic Chemistry – 14.2 – Hydrocarbons: Alkanes
These rules will be introduced by the following examples
Several additional rules will be presented with the examples

15. Organic Chemistry – 14.2 – Hydrocarbons: Alkanes
Example 1:
CH3 – CH – CH – CH2 – CH2 – CH3
CH3
CH2 - CH3
CH3 – CH – CH – CH2 – CH2 – CH3
Root name: hexane
CH3
CH2 - CH3

16. Organic Chemistry – 14.2 – Hydrocarbons: Alkanes
Example 1:
CH3 – CH – CH – CH2 – CH2 – CH3
CH3
CH2 - CH3
CH3
methyl
number carbon chain to locate branches
CH3 – CH – CH – CH2 – CH2 – CH3
Root name: hexane
CH2 - CH3
ethyl
Identify side groups

17. Organic Chemistry – 14.2 – Hydrocarbons: Alkanes
Compound name:
3-ethyl-2-methylhexane
long chain
side group
position on long chain
Additional rule: list side groups in alphabetical order

18. Organic Chemistry – 14.2 – Hydrocarbons: Alkanes
CH3 – CH – CH – CH – CH3
CH3
Example:
CH3 – CH – CH – CH – CH3
CH3
CH3 – CH – CH – CH – CH3
CH3
CH3 – CH – CH – CH – CH3
CH3
No matter how the long chain is selected, the name is the same: 2, 3, 4 - trimethylpentane
CH3 – CH – CH – CH – CH3
CH3
Note the tri; use di, tri, tetra, etc, but don’t use them for alphabetical order

19. Organic Chemistry – 14.2 – Hydrocarbons: Alkanes
Example:
CH3 – CH2 – C – CH3
CH2 – CH3
CH – CH3

20. Organic Chemistry – 14.2 – Hydrocarbons: Alkanes
CH2 – CH3
CH3 – CH2 – C – CH3
CH – CH3
CH2 – CH3
3 – ethyl – 3, 4 – dimethylhexane or
4 – ethyl – 3, 4 - dimethylhexane
Which one???
lowest set of numbers

21. Organic Chemistry – 14.2 – Hydrocarbons: Alkanes
Doing the reverse process is actually easier – draw your long chain and attach the groups in the addressed spots
Start by drawing the long chain without any hydrogens – don’t worry about orientation
Add side groups in their addressed spots
Add hydrogens (each C gets 4 bonds)
Do alkane nomenclature worksheet

22. Organic Chemistry – 14.2 – Hydrocarbons: Alkanes
Physical Properties of Alkanes:
All alkanes are non-polar,
only intermolecular forces = London Dispersion Forces – boiling point and melting point increase with number of carbons (see chart page 551) KNOW
all alkanes are insoluble in water

23. Organic Chemistry – 14.2 – Hydrocarbons: Alkenes
Alkenes are hydrocarbons with 1 double bond
Note dienes and trienes also exist – we’ll focus on compounds with 1 double bond
Alkenes with 1 double bond have the general formula, CnH2n
Since they have 2 less hydrogens than corresponding alkanes, they’re called unsaturated hydrocarbons

24. Organic Chemistry – 14.2 – Hydrocarbons: Alkenes
Alkene formulas:
Alkenes are trigonal planar around the doubly bonded C’s and tetrahedral around the others 3
we won’t use this type

25. Organic Chemistry – 14.2 – Hydrocarbons: Alkenes
Nomenclature of alkenes:
find longest continuous chain of carbons that contains the double bond – same prefixes as for alkanes
add ene to the prefix along with a number to indicate the position of the double bond (for ethene and propene a position number is not needed)
number the long chain from the end closest to the double bond (not the branching)

26. Organic Chemistry – 14.2 – Hydrocarbons: Alkenes
Example:
CH3 – CH2 – CH2 – C = CH2
CH2
CH3
length of long chain containing double bond
side-group
position of side-group
position of double bond
CH3 – CH2 – CH2 – C = CH2
CH2
CH3
2 – ethylpent-1-ene

27. Organic Chemistry – 14.2 – Hydrocarbons: Alkenes
Do questions 10 – 14 on pages 554-5

28. Organic Chemistry – 14.2 – Hydrocarbons: Alkenes
Physical properties of alkenes:
Like alkanes, alkenes are non-polar and are insoluble in water
Boiling points are slightly lower than those for alkanes with the same number of carbons Why?
Smaller # of electrons, weaker LDF lower boiling point

29. Organic Chemistry – 14.2 – Hydrocarbons: Alkynes
Alkynes are unsaturated hydrocarbons with 1 triple bond
General formula CnH2n-2
Alkynes are linear around the triply bonded carbons and tetrahedral around other carbons

30. Organic Chemistry – 14.2 – Hydrocarbons: Alkynes
Alkynes are non-polar aliphatic hydrocarbons like alkanes and alkenes
They are insoluble in water

31. Organic Chemistry – 14.2 – Hydrocarbons: Alkynes
Note that alkynes have higher boiling points than alkanes or alkenes
Obviously the explanation used for alkenes being lower than alkanes doesn’t apply here
Table 14.5, page 557

32. Organic Chemistry – 14.2 – Hydrocarbons: Alkynes
Accepted explanation is that for short chain alkynes, the linear structure around triple bond allows them to come closer together than alkanes or alkenes with same number of carbons, causing stronger London Dispersion Forces

33. Organic Chemistry – 14.2 – Hydrocarbons: Alkynes
Nomenclature of alkynes is identical to that of alkenes, the only exception is the ending:
yne, not ene
Do Practice Problems 16 and 17 on pages 556 and 557

34. Organic Chemistry – 14.2 – Hydrocarbons: Cyclics
Cyclic analogues exist for alkanes, alkenes, and alkynes
General formulas will contain 2 less hydrogens than the open chain hydrocarbons:
cycloalkanes CnH2n, cycloalkenes CnH2n-2, cycloalkynes CnH2n-4
Small cycloalkynes don’t exist because of the large bond strain that would exist around the linear triple bond

35. Organic Chemistry – 14.2 – Hydrocarbons: Cyclics
Line structures are commonly used for the ring part of cyclic hydrocarbons
Always draw them this way
Examples:
CH2
cyclopropane:
not
CH2 CH
not
cyclobutene:

36. Organic Chemistry – 14.2 – Hydrocarbons: Cyclics
Cyclics will always have names ending with cyclo_____ane or cyclo_____ene
Don’t worry about cyclo_____ynes, you will not encounter them, except my favourite one,
Consider the following examples to learn how to do the nomenclature for substituted cyclics
STOP
Name?
stopsyne!

37. Organic Chemistry – 14.2 – Hydrocarbons: Cyclics
CH2 – CH3
ethylcyclopentane
No numbers needed. Why?
CH2 – CH3
Always start at far side of double bond and number clockwise or counter-clockwise towards group
3-ethylcyclopentene
CH2 – CH3
CH3
4-ethyl-3-methlycyclopentene
As above. This one must be numbered counter-clockwise to give lowest set of numbers, even though 1st group gets a higher number

38. Organic Chemistry – 14.2 – Hydrocarbons: Cyclics
CH2 – CH3
CH3
1-ethyl-2-methylcyclopentane
This time the numbering is clockwise since double bond isn’t a factor and when possible lowest number goes on first group
Do Practice Problems 18 – 23 page 559 and 560
Do Aliphatics Review WS
Quiz coming up!

39. Organic Chemistry – 14.1 - Introduction
Classification:
organic compounds
hydrocarbons C and H only
hydrocarbon derivatives C and H along with O, N, and/or halogen atoms
aliphatics without
aromatics with
finished with aliphatics; aromatics today
alkynes – 1 triple bond between C’s – CnH2n-2
alkenes – 1 double bond between C’s – CnH2n
alkanes – all single bonds – CnH2n+2

40. Organic Chemistry – 14.2 – Hydrocarbons: Aromatics
Aromatics: all contain the grouping
Originally this grouping thought to be:
Problems: • all bonds found to be equal length
• this compound should be very reactive but is actually very stable or

41. Organic Chemistry – 14.2 – Hydrocarbons: Aromatics
Today we believe it to be made up of bonds that are neither single nor double but a hybrid of both
We draw the structure
Its name is benzene
Benzene is the root common to all aromatics

42. Organic Chemistry – 14.2 – Hydrocarbons: Aromatics
Nomenclature of Aromatics: page 561
Where numbering starts

43. Organic Chemistry – 14.2 – Hydrocarbons: Aromatics
Examples:
propylbenzene
CH2 – CH2 – CH3
CH3
CH2 – CH3
1-ethyl-3-methylbenzene
CH3 – CH – CH3
2-phenylpropane

44. Organic Chemistry – 14.2 – Hydrocarbons: Aromatics
Do Practice Problems 24 – 27, page 562
Aromatics WS

45. Organic Chemistry – 14.2 – Hydrocarbons: Aromatics

46. Organic Chemistry – 14.3 – Hydrocarbon Derivatives
hydrocarbon derivatives C and H along with O, N, and/or halogen atoms
alkanes – all single bonds – CnH2n+2
organic compounds
hydrocarbons C and H only
aliphatics without
aromatics with
alkynes – 1 triple bond between C’s – CnH2n-2
alkenes – 1 double bond between C’s – CnH2n
alcohols R-OH
akyl halides R-X
carboxylic acids
R-C-OH = O
esters
R1 – C – O – R2

47. Organic Chemistry – 14.3 – Hydrocarbon Derivatives
Hydrocarbon derivatives contain other elements besides C and H; most commonly O, N, or halogen atom
Functional group: group of atoms that gives the compound its characteristic properties

48. Organic Chemistry – 14.3 – Hydrocarbon Derivatives: Alcohols
Alcohols – functional group: “-OH” hydroxyl group
Common alcohols: table 14.7, page 566 3

49. Organic Chemistry – 14.3 – Hydrocarbon Derivatives: Alcohols
Nomenclature of alcohols
Key points – long chain must have “–OH” attached to it
Numbering of the long chain starts from the end closest to “-OH”
Ending of root is ol

50. Organic Chemistry – 14.3 – Hydrocarbon Derivatives: Alcohols
Example
CH3 – CH2 – CH2
CH3 – CH – CH2 – CH2 – OH
side group
position of side group
position of OH
length of long chain containing OH*
CH3 – CH2 – CH2
CH3 – CH – CH2 – CH2 – OH
3-methylhexan-1-ol
* don’t count OH in length of chain

51. Organic Chemistry – 14.3 – Hydrocarbon Derivatives: Alcohols
Example
CH2 – CH – CH2 OH
length of long chain containing OH’s
position of OH’s
number of OH’s
CH2 – CH – CH2 OH
propane - 1, 2, 3 - triol
common name of this compound: glycerol
Advantages to above name??

52. Organic Chemistry – 14.3 – Hydrocarbon Derivatives: Alcohols
Do Practice Problems 28 – 30 on page 567
Omit 28d, 29c, 30a

53. Organic Chemistry – 14.3 – Hydrocarbon Derivatives: Alcohols
Physical properties of alcohols
Because of the hydrogen bonding between OH groups in adjacent molecules,
• alcohols have much higher boiling points than hydrocarbons (1-12 C’s are liquids at SATP)
• small alcohols are totally miscible with water, but ……………

54. Organic Chemistry – 14.3 – Hydrocarbon Derivatives: Alkyl Halides
Alkyl halides contain at least 1 halogen atom, (F, Cl, Br, I)
Alkyl halides are all synthetic compounds
CFC’s (chlorofluorocarbons) are alkyl halides

55. Organic Chemistry – 14.3 – Hydrocarbon Derivatives: Alkyl Halides
Nomenclature of alkyl halides:
long chain must be attached to halogen atom(s)
identical to nomenclature of hydrocarbons
side groups end in o, not yl – fluoro, chloro, bromo, iodo

56. Organic Chemistry – 14.3 – Hydrocarbon Derivatives: Alkyl Halides
Example:
CH3 – CH2 – CH – CH – CH – CH3 Br Cl
CH3 – CH2 – CH – CH – CH – CH3 Br Cl
2, 4 – dibromo – 3 - chlorohexane

57. Organic Chemistry – 14.3 – Hydrocarbon Derivatives: Alkyl Halides
Do Practice Problems 31, 32, page 569
Do Alcohols/Alkyl Halides Nomenclature WS Br Cl
1,4 – dibromo – 2 - chlorocyclohexane

58. Organic Chemistry – 14.3 – Hydrocarbon Derivatives: Carboxylic Acids
Carboxylic acids are weak organic acids containing the carboxyl functional group,
often written –COOH
When carboxylic acids, ionize, the process is:
- C – OH , = O
R - C – OH , = O
R - C – OH(aq) = O
R - C – O-(aq)
H+(aq) + 

59. Organic Chemistry – 14.3 – Hydrocarbon Derivatives: Carboxylic Acids
Common carboxylic acids, acetic acid (active ingredient of vinegar) and citric acid
Nomenclature of carboxylic acids:
In all carboxylic acids the carboxyl group is at one end of the molecule
It is always carbon #1 in the chain

60. Organic Chemistry – 14.3 – Hydrocarbon Derivatives: Carboxylic Acids
Example:
CH3 – C – CH2 – CH2 – C – OH = O
CH2
CH3
CH3 – C – CH2 – CH2 – C – OH = O
CH2
CH3
4, 4 – dimethylhexanoic acid
note that the carboxyl carbon does get counted in the long chain – it is carbon #1

61. Organic Chemistry – 14.3 – Hydrocarbon Derivatives: Carboxylic Acids
Do Practice Problems 33 – 35, page 570

62. Organic Chemistry – 14.3 – Hydrocarbon Derivatives: Carboxylic Acids
Physical properties of carboxylic acids:
Like alcohols they have hydrogen bonding, but hydrogen bonding at 2 sites, -C=O and –OH
This leads to higher boiling points and greater solubility than alcohols with same number of C’s
Carboxylic acids with 1-4 C’s are completely miscible in water

63. Organic Chemistry – 14.3 – Hydrocarbon Derivatives: Esters
Esters have the general formula:
often written RCOOR′
Esters are formed from the reaction of an alcohol and a carboxylic acid; the formation or esterification reaction is the key to naming them
R(or H) - C – O – R′ = O

64. Organic Chemistry – 14.3 – Hydrocarbon Derivatives: Esters
R - C – O - H = O
R - C – O - R′ = O
+ H - O - R′
+ HOH
carboxylic acid
alcohol
ester
water
It’s important that when you look at ester, that you’re able to recognize part that came from alcohol and part that came from acid
Acid part contains C; alcohol part is bonded directly to O O =

65. Organic Chemistry – 14.3 – Hydrocarbon Derivatives: Esters
General form of name:
_______yl _________oate
from alcohol
from acid

66. Organic Chemistry – 14.3 – Hydrocarbon Derivatives: Esters
Examples:
acid part: propanoate
CH3 – CH2 – C – O – CH3 = O
alcohol part: methyl
methyl propanoate
CH3 – CH2 – CH2 – CH2 – O – C – H = O
acid part: methanoate
alcohol part: butyl
butyl methanoate

67. Organic Chemistry – 14.4 – Refining and Using Organic Compounds
Do questions 37 and 38 page 572

68. Organic Chemistry – 14.3 – Hydrocarbon Derivatives: Esters
Physical properties of esters:
fruity odour in some cases
polar but lack of OH bond means no hydrogen bonding, so lower boiling points than alcohols and carboxylic acids
esters with few carbons are polar enough to be soluble in water

69. Organic Chemistry – 14.3 – Hydrocarbon Derivatives
Structural isomers: compounds with same molecular formula but different structural formulas

70. Organic Chemistry – 14.4 – Refining and Using Organic Compounds
Petroleum: mixture of hydrocarbons (primarily alkanes and alkenes) found in natural gas, crude oil, and bitumen (from tar sands)
Petrochemicals: hydrocarbon materials from petroleum used to produce plastics and other synthetic materials

71. Organic Chemistry – 14.4 – Refining and Using Organic Compounds
Fractional distillation: a means of separating petroleum components based on differing boiling points

72. Organic Chemistry – 14.4 – Refining and Using Organic Compounds
Read and discuss page 578 regarding fractional distillation
Fractional distillation is a physical process; mixture is separated into fragments with a small range of boiling points – there is no chemical change in the fractions

73. Organic Chemistry – 14.4 – Refining and Using Organic Compounds
Next stages of petroleum refining are chemical processes:
• cracking – breaks carbon-carbon bonds
• reforming – forms carbon-carbon bonds
alkylation (special case of reforming) forms ,2,4-trimethylpentane from smaller hydrocarbons
Both of these can be divided into many subgroups
Read page and page 581

74. Organic Chemistry – 14.4 – Refining and Using Organic Compounds

75. Organic Chemistry – 14.4 – Refining and Using Organic Compounds