1. Naming with Substituents
Goals for the Day
Isomers
Naming with Substituents
Naming Cycloalkanes
Properties of Alkanes
Combustion of Alkanes
Functional Groups

2. Recall the basics of naming….
Root Names:
1 meth 2 eth prop 4 but 5 pent
6 hex 7 hept 8 oct 9 non 10 dec
Prefix (attached groups)
Root (number of carbons in the main chain)
Suffix (functional group)

3. Substituents…
Alkanes with four or more carbons can have side groups called branches or substituents,
which are attached to the carbon chain.
that replace at least one H on the alkane chain.
When two compounds have the same molecular formula, but differ in the order in which the atoms are bonded, they are called structural isomers.

4. Structural Isomers of C4H10
have the same molecular formula.
have different structural arrangements.
of C4H10 consist of a straight chain and a branched chain, each with 4 carbon atoms.
branch or substituent 4

5. Isomers of Pentane (C5H12)
have the same molecular formula.
have different structural arrangements.
consist of a straight chain and two branched chains. 5

6. Isomers of Alkanes
The number of structural isomers of alkanes increases rapidly as the number of carbon atoms increases.
Insert table of structural
isomers middle pg 420 6

7. Learning Check
Identify each pair of condensed structural formulas as structural isomers or the same molecule. A. B. C. 7

8. Solution
Identify each pair of condensed structural formulas as structural isomers or the same molecule. A.
structural isomers
structural isomers B. C.
same molecule 8

9. Each isomer of a given molecular formula
will have its own unique structure and name.
Let’s look at how to name compounds
that have attachments….
First…what are some of the common
Attachments?....(next slide). 

10. Common Attachments

11. What is the base name of this compound?…What is the name
Of the attachment? One final thing is needed. A number! 
What would the number be for this attachment?

13. Attachment “Rules”
Select the longest chain of carbons first, then go back and determine what the attachments are.
Name the attachment(s). The name of the attachments is in the prefix part of the name of the compound (in front).
The attachment needs a number so you know where it is attached on the chain of carbons.
Number so that the attachment gets the smallest possible number.

14. Your book’s way of naming Alkanes with Substituents14

15. Let’s try to name this compound…
Number so that
What would this name be?

16. Typical alkyl
What would this name be?
4-ethyl octane

17. Try to draw 4-isopropyl decane….

18. A few ways to draw 4-isopropyl decane….

19. If you have groups that are the same, there are prefixes that
can be used … so let’s work on this name…
Typical alkyl

21. With two different groups, you put the attachments alphabetically

22. 4-bromo-6-ethyl nonane

23. Naming Cycloalkanes with attachments…
1 attachment, just add it to the front of the name.

24. So this name is…
Chloro cyclobutane

25. Naming Cycloalkanes with 2 (or more) attachments…
Alphabatize the attachments &
Give the smallest possible numbers.

26. 1-bromo-3-methyl cyclopentane
So this name is…
1-bromo-3-methyl cyclopentane

27. Try to draw 1,4-dichloro cyclohexane…

28. Ways to draw 1,4-dichloro cyclohexane…
Note the use of “di” since the attachments were the same.

29. Two groups… With two groups, you can have stereoisomers
Cis = both groups are on the same side (top or bottom)
Trans = groups are on opposite sides
Trans
Cis

30. Naming with two groups…
Let’s try naming a few compounds together….
(There are some hints on the following slides)…

31. Naming with two groups…
Is this cis or trans ? (remember, that is in the prefix
Part of the name when there are two groups)….

32. This one is cis since the ethyl group and chlorine
are both on the top of the ring (or on the bold lines)
What is the whole name?

33. Cis 1-chloro – 4 – ethyl cyclohexane

34. What is the stereochemistry of this ring?
(Then we will work on the rest of the name!)
Cis
trans

35. This is trans because the bromine and the isopropyl
groups are on opposite sides of the ring. The bromine
is on a dashed line (meaning it’s on the back) and the
isopropy is on a bold line (meaning it’s on the front)…
What is the rest of the name? 

36. The full name is…
Trans 1-bromo-2-isopropyl cyclobutane

37. Last one together…
Is this a) cis or b) trans?....

38. Cis…
It is cis since both of the groups are on the “back” of the structure (on the dashed lines)…

39. This is…
Cis-1-fluoro-2-methyl
cyclopentane

40. You try one in your composition books (I will walk around & check)…
Draw trans-1,3-difloro cyclohexane

41. Should look something like this…
Draw trans-1,3-difloro cyclohexane

42. Alkanes: Physical States
Alkanes are…
gases when they have only 1 to 4 carbon atoms.
liquids when they have 5 to 8 carbon atoms.
solids when they have 9 or more carbon atoms.

43. Alkanes: Solubility and Density
Alkanes are
nonpolar.
insoluble in water.
less dense than water (1.0 g/mL) with a density from (0.62 g/mL to 0.79 g/mL).
Vegetable oil, an organic compound, is not soluble in water.

44. Alkanes in Oil If there is an oil spill,
alkanes in the oil do not mix with the water,
alkanes form a thin layer on the surface of the water spreading large distances,
cleanup includes mechanical, chemical, and microbiological methods
In oil spills, large quantities of oil spread over the surface of the water.

45. Alkanes: Melting and Boiling Points
have the lowest melting and boiling points of all organic compounds.
have only nonpolar bonds, C—C and C—H.
have weak dispersion forces which increase when more carbons are present.

46. Branched Alkanes: Melting and Boiling Points
The boiling and melting points of branched alkanes are lower than their straight-chain isomers because they are more compact.
There is more contact between
hexane molecules (red and black
licorice) than between the surfaces
of 2,3-dimethylbutane molecules
(tennis balls).

47. Analogy…
Neatly stacked, fit well vs. Random packing

48. Cycloalkanes: Melting and Boiling Points
Cycloalkanes have
higher boiling points than straight-chain alkanes with the same number of carbon atoms.
restricted rotation around C—C bonds, maintaining rigid structures.

49. Learning Check
For the following pairs of hydrocarbons, which one has the higher boiling point? Why?
1. Butane or octane
2. Hexane or 2,3-dimethylbutane

50. Solution
For the following pairs of hydrocarbons, which one has the higher boiling point? Why?
1. Butane or octane
Octane (has more carbon atoms) and, therefore, a higher boiling point.
2. Hexane or 2,3-dimethylbutane
Both alkanes have the same number of carbon atoms. Hexane is not branched and, therefore, has the higher boiling point.

51. Combustion of Alkanes Alkanes…
contain single C—C bonds which are difficult to break.
are the least reactive group of organic compounds.
burn readily in the presence of oxygen.
undergo combustion to produce carbon dioxide, water, and energy.

52. Combustion of Alkanes We use methane gas to cook food and heat homes.
Propane gas is used in portable heaters and gas barbecues.
Our cells get energy from the combustion of glucose.

53. Balancing a Combustion Equation…

54. Recommended Order… Write the equation: Balance C: Balance H:
Balance O with O2:

55. Crude Oil
Hydrocarbons in crude oil are separated by their different boiling points in a process called fractional distillation which removes groups of hydrocarbons by continually heating the mixture to higher temperatures.

56. Crude Oil

57. Learning Check
Propane gas is used to provide heat for cooking. Write a balanced equation for the combustion of
propane.

58. Step 1: What is the equation?
Unbalanced equation:
Propane has 3 carbons and therefore 2n+2 hydrogens, or 8 hydrogens
(or you can draw it out & count the # of hydrogens)
To balance the atoms in the formula C3H8, we place a coefficient of 3 in front of CO2 and a coefficient of 4 in front of H2O. The total O in the products is 10 O (6 O in 3CO2 and 4 O in 4 H2O). To balance the 10 O, a coefficient of 5 is placed in front of the O2.

59. Step 2: Balance the carbons…
Unbalanced equation:
Balance C:
To balance the atoms in the formula C3H8, we place a coefficient of 3 in front of CO2 and a coefficient of 4 in front of H2O. The total O in the products is 10 O (6 O in 3CO2 and 4 O in 4 H2O). To balance the 10 O, a coefficient of 5 is placed in front of the O2.

60. Step Three: Balance the Hydrogens
Unbalanced equation:
Balance C:
Balance H:
To balance the atoms in the formula C3H8, we place a coefficient of 3 in front of CO2 and a coefficient of 4 in front of H2O. The total O in the products is 10 O (6 O in 3CO2 and 4 O in 4 H2O). To balance the 10 O, a coefficient of 5 is placed in front of the O2.

61. Step 4: Balance the oxygens…
Unbalanced equation:
Balance C:
Balance H:
Balance O:
To balance the atoms in the formula C3H8, we place a coefficient of 3 in front of CO2 and a coefficient of 4 in front of H2O. The total O in the products is 10 O (6 O in 3CO2 and 4 O in 4 H2O). To balance the 10 O, a coefficient of 5 is placed in front of the O2.

62. Learning Check (You can work this one at home)…
Write a balanced equation for the reaction for the complete combustion of heptane, C7H16.

63. Solution
Write a balanced equation for the reaction for the complete combustion of heptane, C7H16.
Balanced equation:

64. Elements in Organic Compounds
In organic molecules, carbon atoms can form bonds with atoms of O, S, N, P, or halogens,
F, Cl, Br and I. 64

65. Functional Groups Functional groups…
are a characteristic feature of organic molecules that behave in a predictable way.
are composed of an atom or a group of atoms.
are groups that replace a H in the corresponding alkane.
provide a way to classify families of organic compounds. 65

66. Alkenes and Alkynes
Alkenes contain a double bond between adjacent carbon atoms.
Alkynes contain a triple bond.
Aromatic compounds contain a benzene ring. 66

67. Alcohols, Thiols, and Ethers
An alcohol contains the hydroxyl (–OH) functional group.
Thiols contain a
thiol (–SH)
functional group.
In an ether, an oxygen atom is bonded to two carbon atoms (–C–O–C–).
Thiol 67

68. Aldehydes and Ketones
An aldehyde contains a carbonyl group (C=O), which is a carbon atom with a double bond to an oxygen atom, attached to at least one hydrogen atom.
In a ketone, the carbon of the carbonyl group is attached to two other carbon atoms. 68

69. Carboxylic Acids and Esters
Carboxylic acids contain the carboxyl group, which is a carbonyl group attached to a hydroxyl group.
An ester has a carbon attached to the oxygen (not a hydrogen). 69

70. Amines and Amides
In an amine, the functional group is a nitrogen atom.
In an amide, the hydroxyl group of a carboxylic acid is replaced by a nitrogen group. 70

71. Learning Check
Classify each of the following as alcohol, ether, aldehyde, ketone, carboxylic acid, ester, or amine. A. B. C. D. E. 71

72. Learning Check
Classify each of the following as alcohol, ether, aldehyde, ketone, carboxylic acid, ester, or amine. A. B. C. D. E.
alcohol
ether
amine
carboxylic acid
ester 72