What are Isomers?
When two or more compounds having the same formula but different structures are called isomers.
n-butane and Isobutane both have the same chemical formula C 4 H 10 .But they have different structure . .
Explanation for n-butane
- n-butane means Normal Butane
- Formula for normal butane is C 4 H 10
- ‘but’ stands for 4, hence it has 4 carbon atoms
- Number of hydrogen atoms = 2 × Carbon Atoms + 2 = 2 × 4 + 2 = 8 + 2 = 10
Hence we get formula C 4 H 10
In n butane, we show all 4 carbon atoms together as shown below
n-pentane, Isopentane and neopentane all have formula C5H12, but different structures.
Explanation for n-pentane
- n-Pentane means Normal pentane
- Formula for Normal pentane is C 5 H 12
- ‘pent’ stands for 5, hence it has 5 Carbon atoms
- Number of Hydrogen Atoms = 2 × Carbon Atoms + 2 = 2 × 5 + 2 = 10 + 2 = 12
- Hence we get formula C 5 H 12
In n pentane, we show all 5 carbon atoms together as shown below:
Explanation for isopentane:
- The formula for isopentane is also C 5 H 12 however the arrangement is different .
- In this 4 carbon atoms are in a chain and 1 carbon atom forms a branch at the 2nd carbon of the chain. The structure of isopentane is as follows:
Explanation for neopentane:
- The formula for neopentane is also C 5 H 12 , but the arrangement is different.
- In this 3 carbon atoms form the chain and the remaining 2 form branches on the second carbon atom of the chain as shown in the figure below: