Structural isomerism
Structural isomerism
- Isomers have the same molecular formula but a different arrangement of atoms.
- In structural isomerism, the atoms are joined in a different order.
- There are three kinds.
Practice
Isomers are compounds with:
Isomers share a molecular formula but differ in how the atoms are arranged.
The three kinds
- chain isomerism — the carbon chain is branched in different ways (e.g. butane vs 2-methylpropane).
- positional isomerism — the functional group is on a different carbon (e.g. propan-1-ol vs propan-2-ol).
- functional group isomerism — the atoms form a different functional group (e.g. an alcohol vs an ether).
Practice
Chain isomerism is when:
Chain isomers differ in how the carbon skeleton branches (e.g. butane vs 2-methylpropane).
Practice
Positional isomerism is when:
Positional isomers have the same group on a different carbon (e.g. propan-1-ol vs propan-2-ol).
Practice
An alcohol and an ether with the same molecular formula are an example of:
They have the same atoms arranged into a different functional group — functional group isomerism.
You've got it
Key idea
- isomers = same molecular formula, different arrangement of atoms
- structural isomerism = atoms joined in a different order, in three kinds:
- chain (different branching), positional (group on a different carbon), functional group (different group)