Alcohols Flashcards
What are the two ways to produce ethanol?
fermentation, hydration of ethene
What conditions does fermentation need?
Yeast (enzyme catalyst), 37°C, absence of oxygen
Advantages of fermentation
sugar is a renewable resource, low energy input, carbon neutral
Is fermentation actually carbon neutral?
No because of travelling, harvesting
Disadvantages of fermentation
low yield- 15%, product is impure (further distillation required), slow ROR, batch process, loss of habitats to grow crops, land could be used for food
What are the conditions for hydration?
steam, heat, concentrated sulfuric acid catalyst
Advantages of hydration
high yield and purity, fast ROR, continuous process
Disadvantages of hydration
high energy input, ethene is from crude oil
Conditions for dehydration
heat, concentrated sulfuric acid
What is the reagent and condition for the oxidation of alcohols?
acidified potassium dichromate, distillation
What are the observations from distilling alcohols?
If primary or secondary orange to green
What do primary alcohols make?
aldehydes then carboxylic acids
What do secondary alcohols make?
ketones
What do tertiary alcohols make?
nothing
What is a hazard of distilling alcohol?
it’s flammable use a water bath
What method is used to make carboxylic acids?
reflux
What does Tollen’s reagent do?
It forms a silver mirror if aldehyde is present
What does Fehlings do?
creates red brick ppt is aldehyde present
