Alcohols Flashcards
What are the properties of alcohols?
- less volatile than alkenes
- they are polar molecules
- they have have high melting points
- they are water soluble
How are alcohols water soluble?
Having the OH group makes them polar. It therefore can form hydrogen bonds between the polar OH group and the water molecules.
How are alcohols less volatile?
Alcohols are less volatile than alkanes because the intermolecular forces holding alcohol molecules together are stronger than the weak intermolecular forces in alkanes. Therefore it is harder to break the bonds between the alcohols compared to alkanes.
This is why alcohols have a higher boiling point which means that they are less volatile.
What happens to water solubility when the hydrocarbon chain increases?
The influence of the OH group decreases which causes the solubility to decrease.
What are the 3 types if alcohols and rank them from most stable to least?
Tertiary
Secondary
Primary
Primary alcohol + [o] ?
Aldehyde + water
Primary alcohol + 2[o] ?
Carboxylic acid + water
Secondary alcohol + [o] ?
Ketone + water
Preparation of aldehydes?
- acidified potassium dichromate (K2Cr2O7)
- H2SO4
Process of distillation
Preparation of carboxylic acids?
- acidified potassium dichromate (K2Cr2O7)
- H2SO4
Process of reflux
Why does the preparation of carboxylic acid require 2 moles of oxidation agent?
In order to convert from an alcohol to an aldehyde and then into a carboxylic acid.
Preparation of ketones?
- acidified potassium dichromate (K2Cr2O7)
- H2SO4
Process of reflux
Dehydration of alcohols?
Alcohol heated under reflux in the presence of an acid catalyst (H2SO4)
What does dehydrating an alcohol produce?
An alkene
What do substitution reactions of alcohols produce?
Alcohol reacts with hydrogen halides to produce haloalkanes and water.
