O1: 15 Alcohols Flashcards
How are alcohols produced industrially?
By hydration of alkenes in the presence of an acid catalyst.
How is ethanol produced industrially? What are the conditions for this process?
Justify the conditions used.
By fermentation of glucose.
35°C - optimum temperature for enzymes
Anaerobic, with yeast.
What is a biofuel?
A fuel that’s made from biological material that’s recently died.
What are alcohols classified as?
Primary, secondary, and tertiary.
What can primary alcohols be oxidised to?
Aldehydes which can be further oxidised to carboxylic acids.
What can secondary alcohols be oxidised to?
Ketones.
What can tertiary alcohols be oxidised to?
They aren’t easily oxidised.
What is the suitable oxidising agent for alcohols?
Acidified potassium dichromate(VI)
What are the environmental/ethical issues around the use of biofuels?
+ Biofuels are renewable so are more sustainable.
+ Classified as carbon neutral since the CO2 they release was absorbed by the plants when they were growing.
- Switching from fossil fuels to biofuels in transport means petrol car engines would have to be modified.
- Land used to grow crops for fuel can’t be used to grow food.
How can alkenes be formed from alcohols?
By acid-catalysed (concentrated H2SO4) elimination reactions.
What can alkenes formed from alcohols be used for?
To produce addition polymers without using monomers derived from crude oil.
Give equations that show ethanol produced by fermentation is a carbon-neutral fuel.
Photosynthesis:
6CO2 + 6H2O -> C6H12O6 + 6O2
Fermentation:
C6H12O6 -> 2C2H5OH + 2CO2
Combustion:
2C2H5OH + 6O2 -> 4CO2 + 6H2O
Why is ethanol produced by fermentation not carbon-neutral?
Fossil fuels are burned to power machinery used to harvest crops, and to transport the bioethanol.
How is ethanol produced by fermentation separated?
By fractional distillation.
