Isomerism - Organic Chem (7.4) Flashcards
Define isomer
Isomers are molecules that have the same molecular formula but diff. arrangement of atoms
How do isomers of a molecule differ?
They have different names, chemical & physical properties
Name the two main types of isomerism
Structural isomerism & stereoisomerism
Name the 3 types of structural isomerism
- Chain isomerism
- Position isomerism
- Functional group isomerism
Name the 2 types of stereoisomerism
- Geometric isomerism
- Optical isomerism
What is structural isomerism?
When the atoms are connected together in a different order
What is stereoisomerism?
When the atoms are connected together in the same way but arranged differently in space
Describe chain isomerism
Occurs when the carbon chain is arranged differently
Describe position isomerism
Occurs when the C chain remains the same but the position of the functional group changes
What does it mean if a molecule is described as ‘primary’?
The C attached to the functional group is at the end of the chain (attached to only 1 C)
What does it mean if a molecule is described as ‘secondary’?
The C attached to the functional group is attached to two other Cs
What does it mean if a molecule is described as ‘tertiary’?
The C attached to the functional group is attached to 3 other Cs
What is a homologous series?
A homologous series is a group of compounds with similar chemical properties which can be represented by a general formula
Which 4 pairs of homologous series have the same general formula?
Aldehydes & ketones: CnH2nO Carboxylic acids & esters: CnH2nO2 Alkenes & cycloalkanes: CnH2n Alcohols & ethers: CnH2n+1OH
What is functional group isomerism?
When isomers have the same general formula but belong to completely different homologous series
