Alkanes
Carbon has 4
bonding electrons
Carbon can bond
to itself in chains
or rings
Carbon can form
single, double and
triple bonds
Carbon can form
isomers
(same formula, different
names, characteristics and
properties)
Organic Compounds
• Carbon and Hydrogen
(bonded together)
• Excluding OXIDES, CARBIDES,
CARBONATES, CYANIDES
Complete structural diagram
• i.e. 3-methyl heptane
Condensed Structural Diagram
• i.e. 3 methyl heptane
Line Structural Diagram
• Aka Skeleton diagram
• i.e. 3-methyl heptane
ALKANES
• Hydrocarbon compounds
• All carbons are SATURATED
(meaning all single bonds)
• Acyclic (meaning no loops)
CnH2n+2
• i.e. C7H16
IUPAC Naming
• the root is names using the
longest continuous chain of
carbon atoms and applying
the standard greek name
• the suffix “ane” is added to
the appropriate numbering
Prefix
Meth
Eth
Prop
But
Pent
Hex
Hept
Oct
Non
Dec
# of Carbons
1
2
3
4
5
6
7
8
9
10
• every side chain is named by
subtracting the “ane” and
adding “yl” suffix
• each side chain is numbered
by its distance from the first
carbon in the chain (so to
have the lowest numbers)
Example
• Name the following alkane
Example 2
• Name the following alkane
CH3CH2CHCH2CH3
CH3
Example 3
• Name the following alkane
Example 4, 5, 6, 7
• 3,3,4,5-tetramethyl decane
• 3-ethyl 5-methyl octane
• 4-butyl 3-ethyl 2,6-dimethyl nonane
• 3-ethyl 2,3,3-trimethyl heptane
Commercial Importance of Alkanes
• Natural gas = mainly methane (also
includes ethane, propane, butane
and pentane)
• Natural gas is heated in a fractional
distillation town to remove H2S
• Petroleum = variety of alkanes
separated by fractional distillation
• Fuel, wax, lubricants, asphalt, tar and
sulfur all come from petroleum
• Pharmaceuticals, fertilizers,
pesticides and plastics are
manufactured from petroleum
Properties of Alkanes
• Non polar molecules
• as the length of the chain increases, the sum
of the intermolecular forces increases
• shape and size affect the boiling point
• Increase the branching decreases the boiling
point
• Increasing the number of carbons increases
the boiling point