Products from oil Flashcards
What happens in the process of cracking? (In general terms)
Large hydrocarbon molecules are broken down into smaller molecules in the process of cracking.
What type of reactions occur in the process of cracking and what are the products?
How is the first product useful?
Thermal decomposition reactions produce smaller alkanes and alkenes
Alkanes are useful as fuels.
In a displayed structure of an alkene, what does = represent?
How many double bonds does an alkene have?
A double bond
1
What happens when an alkene reacts with bromine water?
They turn the bromine water from orange to colourless.
What is polymerisation?
Give one named example of polymerisation, what happens to the double bond in each ethene molecule in this reaction?
When small molecules called monomers such as alkenes join together to form very large molecules called polymers.
An example is ethene going to poly(ethene), the double bond in each ethene molecule becomes a single bond and thousands of ethene molecules join together in long chains.
Give three general uses of modern polymers.
1) Packaging
2) Clothing
3) Medical applications.
What is a biodegradable substance?
What is the issue with many polymers?
Give three problems with waste disposal?
A substance that can be broken down by microbes when left in the environment.
They are not biodegradable.
Problems with waste disposal include:
1) Increasing eye-sore landfill sites.
2) Nasty smells for people living near landfill sites.
3) The plastic waste can also harm wildlife and takes up valuable space in landfill.
What can be done plastics made from non-biodegradable polymers and why does this mean they can be broken down?
How can these polymers be used?
Plastics made from non-biodegradable polymers can be mixed with cornstarch, microorganisms break down the cornstarch so that the plastic breaks down into very small pieces that can be mixed with soil or compost.
They can be used in food packaging.
What is the formula of ethanol, what does the OH group in the molecule mean?
How else can the formula be written?
How can ethanol be produced? Give two ways.
How can ethene be obtained?
C2H5OH, the OH shows ethanol is an alcohol.
C2H6O
1) Hydration of ethene with steam in the presence of a catalyst (non-renewable), ethene can be obtained from crude oil by cracking.
Fermentation of sugar from plants using yeast. i.e. sugar –> carbon dioxide + ethanol (renewable)
In what two ways can cracking be done?
Cracking can be done either:
1) By heating a mixture of hydrocarbon vapours and steam to a very high temperature.
2) By passing hydrocarbon vapours over a hot catalyst.
What are plastics made of?
Large molecules called polymers.
What are polymers made of?
Polymers are made from many small molecules called monomers joined together.
What are light-sensitive polymers used for?
Light-sensitive polymers are used in sticking plasters to cover wounds so the plasters can be easily removed.
What are hydrogels and what are they used for?
Hydrogels are polymers that can trap water and have many uses such as wound dressings.
What are shape memory polymers and how can they be used?
Shape memory polymers change back to their original shape when temperature or other conditions are changed, an example of this type of smart polymer is a material used for stitchings that changes shape when heated to body temperature.
