What is the Difference Between Position Isomerism and Metamerism?

The main difference between position isomerism and metamerism lies in the changes in the structure and composition of the compounds involved.

Position Isomerism:

1. The position of the functional group changes, but the parent carbon chain remains the same.
2. The isomers have the same molecular formula but different arrangements of atoms.
3. Same alkyl groups are attached to the functional groups in isomers of position isomerism.
4. This type of isomerism belongs to a non-homologous series.
5. Example: 1-Chlorobutane and 2-Chlorobutane.

Metamerism:

1. The functional group remains the same, but the alkyl groups attached to it differ.
2. The isomers have different alkyl groups on either side of the functional group.
3. Different alkyl groups are attached to the functional group in metamerism.
4. This type of isomerism belongs to a homologous series.
5. Example: Diethyl ether and methyl n-propyl ether.

In summary, position isomerism involves a change in the position of the functional group, whereas metamerism involves a change in the type of alkyl groups attached to the same functional group.

Comparative Table: Position Isomerism vs Metamerism

Here is a table comparing position isomerism and metamerism:

Position isomerism is a type of isomerism where the location of the functional group is changed, while in metamerism, the type of alkyl groups in the sides of the functional group is changed. The main difference between position isomerism and metamerism is that position isomerism describes the different locations of a functional group, whereas metamerism describes the structure of alkyl groups attached to a functional group.