alcohols Flashcards
what functional group are alcohols in
hydroxyl functional group (OH)
what is the general formula of alcohols?
CH2n+1 OH
how many carbons do the first five alcohols have
meth-1 carbon
eth-2 carbons
prop-3 carbons
but-4 carbons
pet-5 carbons
what is the formula for ethanol
CH3 CH2 OH
what is the formula for propanol
CH3 CH2 CH2 OH
what is the formula for butanol
CH3 CH2 CH2 CH2 OH
how is the oxidation of alcohols done
by combustion
why are alcohols oxidised when burnt
they react with oxygen in the air
what do some microorganisms use alcohol for
energy source
what are two examples of oxidising agents
-acidified potassium dichromate
-microbial agents
what are uses of ethanol?
-alcaholic drinks
-biofuels
-solvents
what are the two processes of making alcohols
-fermentation
-hydration of ethene
what is the process of fermentation in alcohol production
-carbohydrates from crops break down to sugars
-the sugars are then converted to ethanol by enzymes from yeast
- which do aerobic respiration
what are the conditions needed for fermentation?
-presence of yeast- contain enzymes
-temperature- 35 degrees
-no air in vessels- to prevent oxidation
what is the process of making ethanol from alkenes?
-ethene can be hydrated to make ethanol
-water is added across the double bond
what conditions are needed for hydrating ethene?
-catalyst- phosphoric acid
-temperature- 300 degrees
-pressure- 60-70 atmospheres
what is the percentage yield of fermentation and hydration of ethene
H- around 100%
F-about 15%
what is the purity of fermentation and hydration?
F- low purity- needs fractional distillation
H- high purity
what is the atom economy of fermentation and hydration of ethene
F- 51%
H-100%
what are the advantage of fermentation
-sugar is a renewable source
-only a low temp of 37 degrees is needed
what is the disadvantage of fermentation
- carbon dioxide produced
what is the advantage of hydration of ethene?
-no waste products are made
what are the disadvantages of hydrated of ethene?
-high temp of 300 degrees is needed
-ethene comes from crude oil which is non renewable
