What is the Difference Between Chain Isomerism and Position Isomerism?

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Chain isomerism and position isomerism are two types of structural isomerism, which occurs when molecules have the same chemical formula but different structural arrangements. The main differences between chain isomerism and position isomerism are:

  1. Chain Isomerism: In this type of isomerism, the molecules have the same chemical formula but different carbon backbones. The carbon atoms in the main chain of the isomers are joined together in a different way. For example, there are two isomers of butane, C4H{10}, with one having a straight chain and the other having a branched chain.
  2. Position Isomerism: In position isomerism, the molecules have the same chemical formula, carbon skeleton, and functional groups, but the functional groups are attached to the main carbon chain in different positions. For example, n-butyl alcohol and sec-butyl alcohol are position isomers.

In summary, chain isomers have different carbon backbones, while position isomers have the same carbon skeleton but different positions for functional groups.

Comparative Table: Chain Isomerism vs Position Isomerism

Chain isomerism and position isomerism are both types of structural isomerism, which means that the isomers have the same molecular formula but different arrangements of atoms within the molecule. Here is a table summarizing the differences between chain isomerism and position isomerism:

Feature Chain Isomerism Position Isomerism
Definition Chain isomerism refers to the difference in the arrangement of carbon chains within a molecule. Position isomerism refers to the occurrence of a similar carbon skeleton and functional group, but the functional groups are attached to the main carbon chain in different positions.
Carbon Chains Involves straight or branched carbon chains. The basic carbon skeleton remains unchanged, but the functional groups are positioned differently.
Examples Butane has two chain isomers: n-butane and iso-butane. Alcohols with the formula C4H9OH can exhibit position isomerism, such as the difference between 1-butanol and 2-butanol.

In summary, chain isomerism involves different arrangements of carbon chains within a molecule, while position isomerism involves the same carbon skeleton but with functional groups attached in different positions.