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 .

ELECTRON DOT STRUCTURE OF METHANE - Teachoo.jpg

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

Structure of Methane - Teachoo.png
STRUCTURE OF ETHANE - Teachoo.jpg
SATURATED HYDROCARBON (PROPANE) - Teachoo.jpg

 

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

Structure of Propane - Teachoo.jpg

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

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CA Maninder Singh is a Chartered Accountant for the past 14 years and a teacher from the past 18 years. He teaches Science, Economics, Accounting and English at Teachoo