Alkanes
What are Alkanes:
These are the hydrocarbons in which carbon atoms are linked to each other by a single bond.
Example: Methane
 Formula of Methane is CH _{ 4 }
 There is only one Carbon Atom.
 The 1 Carbon atom has 4 Valence electrons .
 It shares these 4 Valence electrons (1 electron each) with 4 Hydrogen Atoms.
A methane molecule has 1 carbon atom and 4 hydrogen atoms .
General formula for Alkanes:
It Is C _{ n } H _{ 2n+2 }
 Where n is the number of carbon atoms.
Number of Carbon Atoms (n) 
n=1 
n=2 
n=3 
Name of Alkane 
Methane 
Ethane 
Propane 
Structure 



Propane
 In Propane, there are 3 carbon atoms
 The general formula for alkanes is:
C _{ n } H _{ 2n+2 }
 Putting n=3,
C _{ 3 } H _{ 3*2+2 }
C _{ 3 } H _{ 6+2 }
C _{ 3 } H _{ 8 }
Hence, the formula for propane is, C _{ 3 } H _{ 8 }
Name of Alkane 
Formula Derivation C n H 2n+2 
Number of carbon Atoms 
Methane 
CH _{ 4 } 
n=1 
Ethane 
C _{ 2 } H _{ 6 } 
n=2 
Propane 
C _{ 3 } H _{ 8 } 
n=3 
Butane 
C _{ 4 } H _{ 10 } 
n=4 
Pentane 
C _{ 5 } H _{ 12 } 
n=5 
Hexane 
C _{ 6 } H _{ 14 } 
n=6 
Heptane 
C _{ 7 } H _{ 16 } 
n=7 
Octane 
C _{ 8 } H _{ 18 } 
n=8 
Nonane 
C _{ 9 } H _{ 20 } 
n=9 
Decane 
C _{ 10 } H _{ 22 } 
n=10 