Transcript Chapter 12

Chapter 11
ALKANES
Alkanes
• Are hydrocarbons that contain only C-C
single bonds
• General Formula: CnH2n + 2 for compounds
that contain only C and H atoms
Condensed vs Structural Formula
• Condensed Formula:
Ex. CH4
• Structural Formula: shows all bonds
• Ex.
H
|
H - C - H
|
H
IUPAC Nomenclature
• Rule 1. Choose the longest carbon chain.
Designate it as the parent. Branches
from parent are considered as
substituents.
IUPAC Nomenclature
•
•
•
•
•
•
Parent Chain:
1 C - methane
2 C’s - ethane
3 C’s - propane
4 C’s - butane
5 C’s - pentane
6 C’s - hexane
7 C’s - heptane
8 C’s - octane
9 C’s - nonane
10 C’s - decane
IUPAC Nomenclature
•
•
•
•
•
•
Substituent: (ends in -yl)
1 C - methyl
6 C’s - hexyl
2 C’s - ethyl
7 C’s - heptyl
3 C’s - propyl
8 C’s - octyl
4 C’s - butyl
9 C’s - nonyl
5 C’s - pentyl
10 C’s - decyl
IUPAC Nomenclature
• Rule 2. Number the carbon in the parent
chain starting from the end nearest the
substituent.
• In short, substituents must have the lower
numbers.
IUPAC Nomenclature
• Rule 3. Designate the location (position)
and name of each alkyl group before the
name of the parent chain.
• Ex. 2-methylpentane
IUPAC Nomenclature
• Rule 4. List the substituents in
alphabetical order
IUPAC Nomenclature
• Use prefixes if there are more than 1 of a
particular substituent.
• Mono- (1)
Hexa(6)
• Di(2)
Hepta(7)
• Tri(3)
Octa(8)
• Tetra- (4)
Nona(9)
• Penta- (5)
Deca(10)
Haloalkanes and Cycloalkanes
• Nomenclature for haloalkanes:
Same as simple alkanes
•
• Nomenclature of cycloalkanes:
Same as simple alkanes, however, add
the term “cyclo” before parent name
Chemical Properties
• The greater the number of C atoms, the
higher the boiling point.
Reactions
• 1. Combustion:
• Alkane + O2 --> CO2 + H2O + heat