3.3.5.1 Alcohol production
No description yet. This curated deck is ready for daily study.
Card preview (16)
Why do alcohols have higher melting point than alkanes of the same length?
OH in alcohols causes hydrogen bonding which increases the intermolecular forces. Therefore more energy is needed to overcome these forces which increases the melting point
Are alcohols soluble?
The OH group of alcohols can hydrogen bond to water molecules but the non-polar hydrocarbon chain cannot, so alcohols with short chains are soluble
How is ethanol produced from cracking?
Ethene is produced when crude oil fractions are cracked Ethene is hydrated which means that water is added across the double bond Phosphoric acid catalyst
How is ethanol produced by fermentation?
Glucose = Ethanol + Carbon Dioxide Carbohydrates broken down into sugars Converted into ethanol by yeast Carbohydrates come from crops e.g. sugar cane Anaerobic respiration 35 degrees celcius: too low would be slow, too high would denature the enzyme Air kept out to stop ethanol from being oxidised to ethanoic acid At 15% ethanol, enzymes are unable to function. Ethanol can be distilled by fractional distillation
What is the formula for glucose?
C6H12O6
What is the process of making ethanol from crude oil with mechanisms?
See card Step 1: from the double bond to the hydrogen ion Step 2: from electronegative oxygen to positive carbon atom Step 3: from O - H bond to oxygen atom Forms ethanol plus hydrogen
What are the advantages and disadvantages of biodiesel?
Releases less carbon dioxide than mineral diesel from crude oil Fully degradable so is less damaging when spilt Not carbon neutral as energy is required for processing, farming and fertiliser manufacture More expensive to produce than fossil fuels
What are the advantages and disadvantages of bioethanol?
CO2 release is lower than fossil fuels Renewable Less energy dense than petrol Cutting down trees to provide area for growing plants destroys wildlife
What are the advantages and disadvantages of hydrogen?
The only product is water so there are no polluting gases It is an infinite resource It is expensive to electrolyse water Electricity is required to produce hydrogen
What are the properties of alcohols?
Normally polar molecules Soluble in water High melting/boiling points compared to alkenes/alkanes of a similar size
What is the primary, secondary and tertiary structures of alcohols?
See card
Fuel cells
Produce electricity from the reaction between hydrogen and oxygen Efficient at transferring the energy of the reaction Cars with fuel cells are expensive
What is the reaction between alkenes and steam?
Alkene + H2O = Alcohol
What are the conditions for the reaction between ethene and steam?
Ethene + steam (+ phosphoric acid catalyst) = ethanol
What is the reaction for anaerobic respiration?
C6H12O6 ( + yeast ) = 2C2H5OH + 2CO2
What are the conditions for the breakdown of glucose?
Rate is affected by temperature Enzyme denatures at high temperatures Air kept out to prevent oxidation so that ethanoic acid is not produced Ethanol is extracted by fractional distillation