C1 5 Products From Oil Flashcards
What happens during the process of cracking?
A heavy fraction from crude oil is heated to vaporise the hydrocarbons. The vapour is then passed over a hot catalyst or mixed with steam and is heated to a high temperature. The hydrocarbons then crack into smaller, more useful ones as thermal decomposition take place.
What process is used to break down large hydrocarbon molecules?
Cracking
What is the difference between and alkane and alkane?
An alkane is saturated and alkane is unsaturated. An alkane contains as many hydrogen atoms as possible. An alkane contains one Cain double bond. The general formulae for it is CnH2n
What solutions do both alkanes and alkanes form when mixed with bromine water?
Alkanes produce a colourless product where as alkanes give no reaction (Orange)
What are plastics an example of?
Polymers
What are polymers made of?
Monomers
What is formed when ethene and propene are made into polymers? What are their properties like?
Poly(ethene) easy to shape, strong and transparent eg plastic bags
Poly(propene) very strong and tough eg ropes
What is polymerisation?
The process when monomers join together to form polymers.
Explain the process of polymerisation.
When the alkenes molecules join together, the atoms open up and is replace by single bonds.
What makes alkenes more reactor than alkanes?
The carbon double bonds.
What are light-sensitive plasters used for?
To switch off the stickiness of a plaster.
The plaster is put on as usual.
To remove it the top layer is peeled away from the layer which is stuck onto the skin.
When the bottom layer is exposed to light the adhesive becomes less sticky and is easier to peel off.
What are hydrogel a used for?
They are polymer chains with a few cross-linking units between chains which makes a matrix that can trap water. They are used as wound dressings and let the body heal in moist, sterile conditions. This makes them useful for treating burns.
What are shape memory polymers used for?
When it is used to stitch a wound tightly it uses the body’s temperature to tighten the wound and close it.
What is a shape memory polymer an example of?
A smart polymer which changes in response to changes around it.
What are biodegradable plastics?
Plastics that can be broken down by microbes.
What are the disadvantages of biodegradable plastics?
Needs a lot of land and water
Uses pesticides and fertilisers
Destruction of tropical rainforests to create farmland
Farmers may sell food as fuels so food prices rise
What are the advantages and disadvantages of landfill?
Ads: Convenient and cheap Can extract and sell methane Dis ads: Expensive to build and maintain Lorries create traffic Chance of environmental change
What are the advantages and disadvantages of recycling?
Ads: Less landfill Less greenhouse gases Less crude oil used Less water and energy resources used Dis Ads: Only some plastics can be recycled Time and money required to separate plastics
What are the advantages and disadvantages of incineration?
Ads: Less landfill Electricity can be generated from eat Dis ads: Release toxic compounds into atmosphere Waste gases need to be purified
What are the two methods in which ethanol is made?
Fermentation and hydration from ethene
What is the equation for fermentation?
Sugar(glucose) = ethanol + carbon dioxide (+ energy)
Yeast acts as catalyst
What respiration takes place during fermentation?
Anaerobic respiration
What is the reaction for hydration?
Ethene + stems = ethanol Hot water (steam) is catalyst
What are the advantages and disadvantages of fermentation?
Ads: Plants are renewable Energy from sun Dis ads: Slow process Product not pure
What are the advantages and disadvantages of hydration?
Ads: Product is pure Continuous process Dis ads: Uses up fossil fuels Requires high energy Non renewable source of ethene
What are the properties of a thermosoftening plastic?
Flexible and stretchy Low melting point Weak forces between chains Chains are easily separated Polyethene
What are the properties of thermosetting plastics?
Hard High melting point Cross links between chains Hard to break (High melting point) Poly propene
