What process is used to break larger hydrocarbon molecules into smaller one?
Cracking
Describe this process.
Vaporise the hydrocarbon and pass over a hot aluminium oxide catalyst
What is a hydrocarbon?
Compound made from only carbon and hydrogen
What are the products of cracking?
Smaller alkanes and alkenes
What is a catalyst?
Something that speeds up a reaction without being used up
Give 3 uses of the products of alkenes.
Fuels, plastics, ethanol
Give the general formula of alkenes.
CnH2n
Are alkenes saturated or unsaturated?
Unsaturated
How can you test for unsaturation?
Bromine water is decolourised
What special feature does an alkene contain?
Double bond
What do you see if bromine is added to ethene?
Goes from orange to colourless
What is a monomer?
An alkene
What is a polymer?
Many monomers joined together
Give the reaction for the polymerisation of ethene?
Name the product for the polymerisation of ethene?
Polyethene
Give the reaction for the polymerisation of propene?
What feature do polymers not have that the monomers do?
Double bonds
Polymers have many new uses, give 2 examples.
Hydrogels in nappies and waterproof coating like Gore-tex
Many polymers are not biodegradable, what does this mean?
Don’t break down
Give 2 problems with polymers not being biodegradable.
Fill up landfill sites and produce litter
Some plastic bags are made from cornstarch polymer why is this useful?
Renewable and biodegradable
List 3 ways in which polymers are disposed of.
Incineration, landfill and recycle
Give an advantage and disadvantage for incinerating polymers.
Give out energy
Give out carbon dioxide which leads to global warming
Give an advantage and disadvantage for putting polymers in landfills.
Easy
Don’t biodegrade so they get filled up
Give 3 advantages of recycling polymers.
Less waste in landfills
Not wasting a non-renewable resource
Less pollution produced and energy used
Give 2 disadvantages of recycling polymers.
Collecting and sorting
Transportation
Give a word equation for the production of ethanol through fermentation.
Glucose + water → ethanol
Describe the process of fermentation.
Add sugar and yeast to warm water in the absence of oxygen
Describe another method of making ethanol
Reacts ethene with steam
Give a symbol equation for the reaction of ethene and steam.
C2H4 + H2O → C2H5OH
If ethanol is combusted what are the products?
Carbon dioxide and water
How much ethanol is produced in fermentation?
Less than 15%
Which process of making ethanol is continuous?
Ethene method
Which process of making ethanol uses non-renewable raw materials
Ethene method
Which process of making ethanol is completed in batches?
Fermentation method
Which process produces pure ethanol?
Ethene method
Give advantages and disadvantages for the fermentation method
cheap raw material
Renewable plant material
Low temperature
batch method so slow
Impure ethanol
Give advantages and disadvantages for the ethene method
pure ethanol
fast
uses non-renewable fossil fuels
high energy costs
