Alcohols Flashcards
What is fermentation of glucose?
process that uses living yeast cells to convert into ethanol and carbon dioxide
What are the conditions for the fermentation of glucose?
yeast provides enzymes that act as catalyst
37°C so enzymes don’t denature
No O2 anaerobic respiration
What are some advantages of fermentation?
low energy input
sugar cane is renewable
What is a biofuel?
product is derived from plants/animals
What is it meant by carbon neutral?
no net emissions of carbon dioxide
(CO2 released is balanced by CO2 taking in by photosynthesis)
Why is the fermentation of glucose not truly carbon neutral?
CO2 will be made from other processes
(burning the fossil fuels and transportation)
which 3 processes show carbon neutrality?
(in order that they happen)
photosynthesis
fermentation
combustion
what is the equation for photosynthesis?
carbon dioxide + water > oxygen + glucose
What is the equation for fermentation?
glucose > ethanol + carbon dioxide
what is the equation for combustion of ethanol?
ethanol + oxygen > carbon dioxide + water
What are some disadvantages of fermentation?
low yeild
product is impure further distillation required
slow rate of reaction
**environmental issues ** loss of habitat
What is the equation for the direct hydration of ethene?
ethene + water > ethanol
What ate the conditions for the direct hydration if ethene?
steam
heat
conc H2SO4 as a catalyst
Shat are some advantages of the direct hydration of ethene?
high yeild and purity
fast rate
continuous process
What are some disadvantages of the direct hydration of ethene?
high energy input required
ethene is obtained from crude oil which is non renewable
What is the equation for the dehydration of ethanol?
ethanol > water + ethene
What are the conditions for the dehydration of ethanol?
heat
concentrated sulphuric acid as catalyst
what are the observations when potassium dichromate oxidises alcohol?
colour changes from orange to green
What is formed when primary alcohols are oxidised?
Aldehydes
How are primary alcohols oxidised?
using potassium dichromate under the conditions of distillation
What is formed when Aldehydes are oxidesed?
carboxylic acids
How is an Aldehyde oxidised?
using acified potassium dichromate
under conditions of reflux and excess acid
What is the equation for ethanol being oxidised to ethanal?
CH3CH2OJ + [O] > CH3CHO + H20
ethanol. ethanal. water
(O) = oxidising agent
What is the equation for the formation if a carboxylic acid from a primary acid?
CH3CH2OH > 2[O] > CH3COOH + H2O
What is formed when secondary alcohols are oxidised?
Ketones
How are secondary alcohols oxidised ?
under conditions of distillation
Why can ketones not be oxidised further?
C-C bond is too strong
What is distillation?
separates a mixture of liquids with different boiling points
What are the conditions for the reactants during oxidation of a primary alcohols to a carboxylic acif
reactants should be heated together under a reflux
