CHEM - 15. Alcohols, carboxylic acids, esters (not done)

what is the functional group of alcohols

-OH

how many isomers can propanol have and what are their names

2 isomers

propan-1-ol

propane-2-ol

describe the flame of the combustion of alcohols

they burn with a clean flame and produce carbon dioxide and water

what can alcohols be oxidised to using oxidising agents such as potassium dichromate

carboxylic acids

what does the oxidation of ethanol produce

ethanoic acid and water

list the raw material for fermentation of sugars v reaction of ethene with steam

source of carbs e.g. sugar cane, maize

crude oil

list the raw material for fermentation of sugars v reaction of ethene with steam

source of carbs e.g. sugar cane, maize

crude oil

list the reaction for fermentation of sugars v reaction of ethene with steam

sugar —> ethanol + carbon dioxide

ethene + water —→ ethanol

list the conditions for fermentation of sugars v reaction of ethene with steam

30-40C, so enzymes dont denature - yeast (contains enzyme zymase) - water - anaerobic (no Oxygen present)

300C - concentrated phosporic acid catalyst - 60-70 atm pressure

list the type of process for fermentation of sugars v reaction of ethene with steam

batch - start stop process which is labour intensive

continuous process - kept running 24/7 which is less labour intensive

list the rate for fermentation of sugars v reaction of ethene with steam

slow

fast

list the purity for fermentation of sugars v reaction of ethene with steam

impure ethanol, must purify by fractional distillation

pure

carboxylic acids?

name the organic product that is formed when ethanol is left open in air

ethanoic acid (vinegar)

what colour change is seen when ethanol is warmed with acidified potassium dichromate solution

orange to green

what is bioethanol

renewable biofuel, derived from plant-based biomass, used primarily as a cleaner alternative to gasoline

how is bioethanol produced

fermenting sugars and starch from plant-based materials e.g. corn, sugar cane. Then further dehydrated to achieve higher purity

advantages of fermentation method to produce ethanol

• renewable, environmentally friendly

• cheaper

• only requires carbs, no energy required

disadvantages of fermentation method to produce ethanol

• slow

• produces impure ethanol that requires separating

why might ethanol become a more important and popular fuel for cars in future

• reduces emissions, no green house gases produced

• renewable

2 advantages of using ethanol instead of petrols in cars

• cleaner combustions

• petrol contains impurities

• higher proportion of fuel burns efficiently

what does carbon neutral mean

every molecule of CO2 produced is absorbed by plants

2 disadvantages of using ethanol instead of petrol

• less energy per gallon

• highly flammable