1. Chapter 3
Organic Chemistry

2. Chapter A3
A3.1 – Organic Compounds

3. Organic chemistry
the word “organic” means of, relating to, or derived from living organisms
organic chemistry is defined as the study of the molecular compounds of carbon
compounds containing carbon-based ions (e.g. carbonate) are not considered to be organic compounds because they contain ionic bonds

4. Organic chemistry
of the over 10 million chemical compounds that have been discovered, at least 90% are carbon-based molecular compounds
the properties of organic compounds are a result of the covalent bonds within their molecules
recall, covalent bonds occur when the valence electrons of two non-metals are shared

5. Carbon as a building block
carbon has the highest number of bonding electrons of any element
4 bonding electrons
because of its high bonding capacity, carbon atoms have the ability to form chains, rings, spheres, sheets, and tubes of almost any size
carbon can also form single, double, and triple covalent bonds

6. Illustrating organic compoundsH
Lewis dot diagrams are useful for the small and simple molecules…
but are awkward with the larger, more complex molecules found in organic chemistry.

7. Illustrating organic compounds
one way to speed up the process is to expand the molecular formula into clusters of carbons
e.g. CH3-CH2-CH2- etc…
to the right are six different ways of illustrating the compound C5H12:
1 – the Lewis dot diagram
2 – complete structural diagram
3 – condensed structural diagram
4 – expanded molecular formula
5 – simplified structural diagram
6 – line structural diagram

8. Classifying organic compounds
in order to manage the enormous number of different organic compounds, chemists divide them into families based what makes the compound special
types of bonds
single,
double or
triple H

9. Functional groups
groups of atoms with elements other than carbon and hydrogen
these additional groups are responsible for the unique properties of some compound groups
Ex. ethanol CH3–CH2 –OH, has the hydroxyl functional group (-OH) which gives the compound its physical and chemical properties, such as higher solubility, & flammability.

10. Alkanes
hydrocarbons are compounds containing only carbon and hydrogen atoms
alkanes are hydrocarbons with only single carbon-to-carbon bonds
the general formula for all alkanes is CnH2n+2
as the size (and molar mass) of an alkane increases, the boiling point increases
bigger molecules will have MORE BONDS, so MORE ENERGY is needed to break them apart to change state

11. Alkanes name formula methane CH4 (g) ethane C2H6(g) propane C3H8(g)
butane C4H10(g)
pentane C5H12(l)
hexane C6H14(l)
heptane C7H16(l)
octane C8H18(l)
nonane C9H20(l)
decane C10H22(l)
- ane CnH2n+2
All alkane names end in – ane
The prefix (beginning of the word) indicates how many carbons are in the chain
Ex. Meth = one cartbon,
eth = two, prop= 3, etc…
notice that the first four (the smallest ones) are gases,
the next twelve are liquids,
it isn’t until the molecules get very large (C17H36)that are big enough to be solid

12. Naming alkanes: Step #1:
identify the longest continuous chain of carbon atoms ( the parent chain) in the structural diagram
Note: they may not be in a straight line, but all must be connected

13. Naming alkanes: Step #2:
number the carbon atoms in the parent chain, starting from the end closest to a branch.
Name it! The number of carbons determines what the prefix is.
Only singled bonds, means it ends in –ane
See page 9 of your data booklet for the complete list of alkanes
four carbons
= butane
three carbons
= propane

14. Naming alkanes: Step #3:
identify any branches and their location, using a number on the parent chain.
branch names always end in –yl
the prefixes (meth = one carbon, eth = two, prop= 3, etc…) indicates how many carbons are in the branch
if the compound has more than one of the same type of branch, the number of BOTH locations is listed, and a prefix is provided
TWO single carbon branches BOTH on the second carbon of the parent chain
one single carbon branch on the second carbon of the parent chain
= 2,2-dimethyl ___
= 2-methyl___

15. Naming alkanes: Step #4:
write the complete IUPAC name, following this format:
(number of locations) – (branch name)(parent chain)

16. Now put it all together…
* one, two carbon branch on carbon 5
= 5-ethyl
10 carbon parent chain
= decane
* four, one carbon branches on carbon 3, 4, 4 & 6
= 3,4,4,6-tetra methyl
where there are more than one type of branch group, (some with one carbon; methyl, and others with two carbons; ethyl) the branches are named in alphabetical order (E-thyl before M-ethyl)
Now put it all together…
5-ethyl
-3,4,4,6-tetra methyl
decane

17. Practice 1:
Name this compound:

18. Practice Problem #1: Answer
Step #1 & 2:
the parent chain is identified and numbered, beginning at the end closest to the first branch.
6 carbons = hexane
Step #3:
the first branch is identified as a single carbon branch (methyl), on C#2.
methyl on 2 = 2methyl
_________-2-methyl_________

19. Practice Problem #1: Answer
Step #3 cont:
a second branch is identified as a two carbon branch(ethyl) on C#3
ethyl on 3 = 3-ethyl
Step #4:
Put it all together!
remember, where there are more than one branch group, the branches are named in alphabetical order
(ethyl before methyl).
3-ethyl__________________

20. To draw alkanes: Step #1: pentane = 5 carbon parent chain
to draw alkanes, use the IUPAC name, starting from the BACK of the compound name:
Ex. 3-ethyl-2,4-dimethylpentane
Step #1:
identify the name of the parent chain and the corresponding number of carbon atoms:
pentane = 5 carbon parent chain
draw the skeleton of the parent chain

21. To draw alkanes: Step #2:
identify the type of branches and position them on the appropriate carbons on the parent chain.
Draw them in!
2,4-dimethyl = TWO single carbon
branches on the second and fourth carbon
3-ethyl = ONE double carbon branch on the third carbon

22. To draw alkanes: Step #3:
fill-in any unfilled bond sites with hydrogens.
Don’t add too many! Remember each carbon has a MAXIMUM bonding capacity of 4!

23. Try These! Draw the complete structural diagram for: ethane
4-propyloctane
2,2,4,5-tetramethylhexane
NOT

24. Assignment: Practice Problems (page 110) 3.1 Summary (page 121)
Q. 1-4 (a & c only)
3.1 Summary (page 121)
Q’s 4, 5 (a,c,e 7 g) & 6

25. Assignment: Complete the Alkanes Worksheet
You must submit your work by the end of class

26. Chapter A3
A3.2 – Alkenes & Alkynes

27. Alkenes and alkynes
Alkenes and alkynes are hydrocarbons with double and triple bonds
hydrocarbons with double bonds are called alkenes, and with triple bonds are called alkynes.
these compounds are named in a similar way to alkanes, (using prefixes to indicate the number of carbon atoms), but their names will end in –ene and –yne.
triple bond
triple bond
ethyne

28. Alkenes and alkynes
name formula ethene C2H4(g) propene C3H6(g) butene C4H8(g) pentene C5H10(l) hexene C6H12(l) heptene C7H14(l) octene C8H16(l) nonene C9H18(l) decene C10H20(l)
name formula ethyne C2H2(g) propyne C3H4(g) butyne C4H5(g) pentyne C5H8(l) hexyne C6H10(l) heptyne C7H12(l) octyne C8H14(l) nonyne C9H16(l) decyne C10H18(l)
recall the general formula for alkanes was CnH2n+2
the general formula for alkenes is CnH2n
and for alkynes is CnH2n-2

29. stability of organic compounds
the type of bond affects the chemical properties, such as reactivity, and physical properties, such boiling point, melting point and solubility.
a compound will be MORE STABLE if it is larger
this is because it has more carbon-carbon bonds to break during the reaction
OR if it DOES NOT contain multiple bonds
alkenes and alkynes (double or triple bond) are relatively easy to break
this is because it has more hydrogen bonds are a stabilizing force in a molecule

30. MORE STABLE compounds have:
higher melting point/ boiling point
are less reactive
more likely to be found in solid form

31. Solubility recall the phrase “like dissolves like”
polar solutes dissolve easily in polar solvents.
water is polar, so it easily dissolves ionic compounds, acids, and polar molecular compounds
Ex. salt, hydrochloric acid or ethanol
alkanes, alkenes and alkynes are NON-POLAR, so they dissolve better in a non-polar solvent (like oil) than a polar one, such as water.

32. Practice problem: pentane, butane, propane propene, propane, propyne
Rank the following compounds in order of lowest to highest boiling point
pentane, butane, propane
propene, propane, propyne
Rank the following compounds in order from least to most reactive
ethyne, nonane, pentene
octane, heptene, octene

33. Practice problem Answers:
Rank the following compounds in order of lowest to highest boiling point
pentane, butane, propane
MORE STABLE if it is larger = higher boiling point…must rank smallest to largest
propane (3 C’s) butane (4 C’s) pentane (5C’s)
propene, propane, propyne
MORE STABLE if it contains ALL single bonds = higher boiling point …must rank from least to most single bonds
propyne (triple bond)  propene (double bond)  propane (single bonds)

34. Practice problem Answers:
Rank the following compounds in order from least to most reactive
ethyne, nonane, pentene
MORE STABLE if it is larger and/or if it contains ALL single bonds = less reactive…must rank from smallest with most double/triple bonds.
nonane (largest-9 C’s & single bond)  pentene (5 C’s & double bond)  ethyne (smallest-2 C’s & triple bond)
octane, heptene, octene
octane (largest-8 C’s & single bond)  octene (8 C’s & double bond)  heptene (smallest-7 C’s & double bond)

35. Naming alkenes and alkynes
Naming alkenes and alkynes is similar to naming alkanes;
using prefixes to indicate the number of carbon atoms and the ending indicates the type of bond
alkanes end in –ane
alkenes end in –ene
alkynes end in -yne
Since the location of a multiple bond affects the chemical and physical properties of a compound the name of the compound must specify the location of the multiple bond

36. pent-1-ene indicates the double bond is located between the 1st and 2nd carbons of the parent chain
pent-2-ene indicates the double bond is located between the 2nd and 3rd carbons of the parent chain

37. Naming alkenes and alkynes
the rules for naming are similar to alkanes, with three additional rules:
Step #1: find the longest continuous carbon chain; this is the parent chain. Use the number of carbons to determine which prefix
for alkenes and alkynes the parent chain must contain the multiple bond
five carbons = pent-
double bond = - ene

38. Naming alkenes and alkynes
Step #2: to determine the location of the double/triple bond, the parent chain is numbered
for alkenes and alkynes you start numbering from the end closest to the multiple bond (not closest to the first branch as for alkanes) 1 2 3 4 5
bond between 2 & 3 = _____-2- ______

39. Naming alkenes and alkynes
Step #3: identify any branches and their location, using a number on the parent chain (just like with alkanes).
count from the SAME side you started numbering the bond from
branch names always end in –yl
Two carbon branch on third carbon = 3-ethyl _________

40. Step #4: 3-ethylpent-2-ene
write the complete IUPAC name, following this format:
(number of locations)–(branch name)(prefix of carbon chain-location of bond- suffix of parent chain)
3-ethylpent-2-ene
five carbons = pent-
double bond = - ene
bond between 2 & 3
Two carbon branch on third carbon

41. Try This:
Name the following compound

42. Practice problem (Answer)
five carbons = pent-
triple bond = - eye
bond between 2 & 3
identify any branches
single carbon branch on fourth carbon
= 4-methyl
Put it all together

43. To draw alkenes/Alkynes:
to draw alkenes and alkynes, use the same rules as you did for drawing alkanes,
use the IUPAC name, starting from the BACK of the compound name:
Ex. 2,5-dimethylhept-3-yne
Step #1:
identify the name of the parent chain,
the corresponding number of carbon atoms AND the type/ location of the bond
hept- = 7 carbon parent chain,
3-yne is a triple bond on the third carbon
2,5-dimethylhept-3-yne

44. Draw the skeleton
Remember the maximum bonding capacity of carbon is 4… so that will affect the number of hydrogens on some of the carbons in the parent chain.
Since there are THREE bond in between the C’s and one, connecting to the rest of the chain there is NO ROOM for any hydrogens. 1 2 3 4 5 6 7

45. To draw alkenes/ alkynes :
Step #2:
identify the type of branches and position them on the appropriate carbons on the parent chain.
Draw them in!
2,5-dimethylhept-3-yne
2,5-dimethyl = TWO single carbon
branches on the second and fifth carbon 1 2 3 4 5 6 7 C H C H

46. To draw alkenes/Alkynes :
Step #3:
fill-in any unfilled bond sites with hydrogens.
Don’t add too many! Remember each carbon has a MAXIMUM bonding capacity of 4! 1 2 3 4 5 6 7 C H 1 2 3 4 5 6 7 C H

47. Isomers
Isomers are compounds containing the same number of carbons and hydrogens but in different arrangements
Isomers have the same formula, but different structural diagrams.
C7H 16
-di
C7H 16

48. Practice problem: Draw the following isomers pentane 2-methylbutane
2,2-dimethylpropane
What is the chemical formula for each isomer?

49. Alkenes and alkynes
if an organic compound has carbon-carbon double bonds, it is said to be unsaturated.
the addition of hydrogen molecules, to an unsaturated is called hydrogenation and results in a saturated hydrocarbon
the term saturated means “full” so think of alkanes are being “full” of hydrogens, where alkenes and alkynes ARE NOT
vs.

50. Alkenes and alkynes
to become saturated, the double (or triple) bond breaks, and the hydrogen atoms take the place of the multiple bond
this reaction is called an addition reaction H H
there must always be enough hydrogens in an addition reaction to fill all the unbonded sites.
Alkynes have triple bonds so TWO hydrogen molecules (4 hydrogens) are required to fill the bonding sites
+ 2

51. halogenation
alkenes and alkynes also tend to react readily with other small diatomic molecules such as the halogens
F2 , Cl2, Br2 , & I2
Like with a hydrogen addition reaction, some of the bonding sites once occupied by multiple carbon-carbon bonds become filled with a halogen
Cl - Cl Cl

52. Fats and Oils
The terms saturated and unsaturated are often used in combination with “fats”
animal fats and plant oils can be a good source of energy.
fatty acids (aka fats) are organic molecules made of
a long chain of carbons with a -COOH group at one end
and a methyl group at
the other end

53. Oils
Recall that the structure of a molecule affects it physical and chemical properties
oils tend to be unsaturated fats—(containing double or triple bonds)
this causes the molecule to bend, which is why the molecules can pack together as tightly.
This is why they tend to be liquids at room temperature

54. Fats
Fats (either manmade or from animals) tend to be saturated fats—(containing ONLY single bonds)
this causes the molecule to straight, so they can pack tightly together.
This is why they tend to be solids at room temperature.
Their solid sate AND the fact that they are alkanes (containing all single bonds) mean they are VERY stable
this means they have HIGH boiling/ melting points

55. Unsaturated fats
monounsaturated fats –have one double bond (and two fewer hydrogens than a saturated fat)
polyunsaturated fats – have more than one double bond, (so even fewer hydrogens)
unsaturated fats are better for the body
hydrocarbons with double or triple bonds are more reactive/easy to break down = less work for our bodies to break down
saturated fats are harder for your body to break down, so they stick around and cause “body fat”.

56. Essential Fatty Acids
essential fatty acids are fats your body can’t make, and are found only in certain foods
“omega-6” fatty acids are found in margarine, processed foods, corn oil and soybean oil
while these fats are important for clotting and inflammation, many people eat too many omega-6s
“omega-3” fatty acids are found in some fish, flax seeds, and enriched eggs
these fats have the opposite effect as omega-6s – they reduce swelling and slow blood clotting, so a balance between the two is important

57. Trans fats
“Cis” and “Trans” refer to different 3D arrangements of a molecule
“Cis” fats are naturally occurring, but can be made into “Trans” fats through a hydrogenation
the addition reaction involving hydrogen.

58. Trans fats
Because they are synthetic, trans fats are the hardest for your body to break down, and are the worst kinds of fat.
Trans fats are found in many processed foods and fast foods because
they are in solid form, so they are easier to work with than oils
they are softer and easier to spread that typical animal fats
you need less trans fats to have the same effect on a food, so they qualify for a “low fat” label, even though the fats are much worse for you
Because food manufacturers are allowed to put up to 0.5g of trans fats in their food and still label it as “trans fat free”, be sure to check ingredients labels for partially hydrogenated oils

59. Assignment: Practice Problems (pg 129) Q. 28 & 29
** CAUTION! Your textbook uses the old IUPAC naming system, where the location of the bond goes BEFORE the parent chain. You must use the current method:
Ex. A hydrocarbon with a double bond between the 1st and 2nd carbon: you SHOULD write hex-1-ene, your textbook writes it as 1-hexene
Practice Problems (pg 132)
Q’s 31
3.2 Summary (pg 136)
Q’s 3 & 4, 8 &10

60. Assignment: Try This Activity Complete the
Building Models of Hydrocarbons

61. A3.3 &3.4 - Industrial Processes Involving Organic Compounds
Chapter A3
A3.3 & Industrial Processes Involving Organic Compounds
Assignment:
Use the “Fractional Distillation” applet, to complete the Utilizing Technology: From Petroleum to Gasoline
Complete the Ch 3.4-Everyday uses of Hydrocarbons Inquiry Questions