Chain isomerism

1. Chain isomerism :
2. The structural isomerism in which compounds have the same molecular formula but differ in the arrangement of their carbon chains.
3. This difference may be due to straight-chain or branched-chain structures.The carbon atoms are connected in a straight or branched way.

Examples:

1. 1.Butane (C₄H₁₀):
2. n-Butane: CH₃–CH₂–CH₂–CH₃ (straight chain)    and
3. Isobutane: CH₃–CH(CH₃)–CH₃ (branched chain).
4. 2.Pentane (C₅H₁₂):
5. n-Pentane: CH₃–CH₂–CH₂–CH₂–CH₃
6. Isopentane : CH₃–CH(CH₃)–CH₂–CH₃
7. Neopentane : C(CH₃)₄.