Zusammenfassung der Ressource
Carboxylic Acids
- Physical Properties
- Soluble in organic solvents
- Smaller chains are soluble in water (due to hydrogen bonding)
- Small ones readily dissolve in cold water
- As mass increases, solubility decreases
- Boiling point: Increases as size increases, due to increased number of London forces
- Boiling point is higher for straight chain isomers
- Greater branching = lower inter molecular forces = lower boiling point
- Carboxylic acids have high boiling points for their relative mass
- This arises from inter-molecular hydrogen bonding due to polar O-H bonds
- Dimerisation doubles the size of the molecule therefore increasing the London forces between itself and its neighbour
- Extra inter-molecular attraction = more energy required to separate molecules
- Naming
- >Select the longest chain of Carbon atoms containing the COOH group
- >Remove the e and add oil acid after the basic name
- >Number the chain starting from the end nearer the COOH group
- >As in alkanes, prefix with alkyl substituents
- >Side chain positions are based on the C in the COOH being 1
- e.g. CH3 - CH(CH3) - CH2 - CH2 - COOH