Alcohols Flashcards
What are the classifications for alcohols?
Primary, Secondary and Tertiary
Why are there primary, secondary and tertiary alcohols?
As the carbon the -OH is bonded to has a different number of R groups.
Primary has one
Secondary has two
Tertiary has three
Why do alcohols have a higher Bp then alkanes of a similar Mr?
As the -OH group allows for hydrogen bonding between the molecules.
Are alcohols soluble in water?
Only short chained alcohols are soluble as the -OH group can hydrogen bond to water as it is polar.
Long chained alcohol have along non-polar chain which dominates and are therefore insoluble.
What are some purposes of alcohols?
Cosmetics- perfumes and aftershaves
Drugs
Alcoholic beverages
What are the two methods of ethanol production?
-Cracking of ethane
-Fermentation
Describe how ethanol is produced by fermentation?
-Plant carbohydrates are broken down into glucose
-Yeast anaerobically respires and then converts glucose into ethanol
-Takes place at 35°c
-Air is kept out to prevent the formation of ethanoic acid(vinegar)
-Once it reaches 15% ethanol the enzymes can’t function so the ethanol is distilled as it has a BP of 78°c
How is ethanol produced from Ethene?
Ethene is hydrated (water is added) in the presence of concentrated phosphoric acid.
Why and how is ethanol used as fuel?
Ethanol is extremely flammable and can be used as a fuel in camping stoves where methanol is added to make it unsafe to drink so there is no alcohol tax on the fuel. It is dyed to show it should not be drunk.
What are the products from a slow oxidisation of alcohols?
Aldehydes and Ketones
How are aldehydes formed?
When a primary alcohol is oxidised in excess without reflux.
How are ketones formed?
When secondary alcohols are oxidised with the agent in excess and with reflux
Why can’t tertiary alcohols be oxidised?
As a C-C bond would need to break which is unfavourable.
