Fuels (paper 2) Flashcards
Name two natural resources
Natural gas and crude oil
What is a finite resource
They won’t last forever, there is limited supply due to them either being made very slowly or not at all
What is crude oil a complex mixture of
Hydrocarbons
What is a hydrocarbon made up of
Hydrogens and carbons
How many covalent bonds can a carbon make
4
Name two uses of crude oil
Feedstock and fuels for vehicles
What is natural gas a mixture of
Hydrocarbons in gas state
What is natural gas useful for
Cooking
Name three things that can be obtained from crude oil
Diesel, petrol and kerosine
What is meant by non renewable
We are using them up fast than they are being made
How can more useful forms of crude oil be obtained
By fractional distillation as the different hydrocarbons have different melting points
Where does industrial fractional distillation occur
In an industrial fractionating column
The separate liquids and gases are called what
Oil fractions because they are only part of the crude oil
The hydrocarbons in the gases fractions have the lowest what
Viscosity and are the easiest to ignite
Bitumen is solid at what
Room temp and also waterproof
What is bitumen and the gases used for
Bitumen is used for surfacing roads and the gases are used as fuels
What are the compounds in crude oil mostly
Alkanes
What are alkanes
Hydrocarbons with one covalent bond
What does a homologous series have in common
Gradual variation in physical properties
Similar chemical properties
What is the general formula for alkanes
CnH2n+2
Give an example of an alkane
Ethane is C2H6
What do alkanes produce when they react with excess oxygen
Carbon dioxide and water
Explain combustion
Hydrocarbons reacting with oxygen in the air when they burn, which is oxidation
Complete combustion of a hydrocarbon is when
Only carbon dioxide and water is produced
Energy is given out
When does incomplete combustion happen
When there is limited air or oxygen
What happens during incomplete combustion of a hydrocarbon
Water is produced
Energy is given out but less than complete
Carbon monoxide and carbon are produced
During incomplete combustion, what can carbon be released as
Smoke or soot
Why is carbon monoxide toxic
It combines with haemoglobin in red blood cells which stops oxygen from being combined
Why is soot a problem
It can block pipes carrying waste gases, blackens buildings and causes breathing problems if it collects in the lungs
What makes acid rain acidic
Sulphur dioxide
What is sulphur dioxide in hydrocarbons know as
An impurity
What is done with these impurities
Mostly removed at oil refineries to reduce environmental impacts
What are some affects of acid rain
Crops won’t grow if the soil is too acidic, prevents fish eggs from hatching if water courses are too acidic, increases the rate of weathering on buildings and corrosion of metals
Name an atmospheric pollutants that is made by engines
Nitrogen oxides
What is an affect of nitrogen dioxide
It can cause respiratory issues such as bronchitis
What is used by oil refineries to meet supply with demand
Cracking
What does cracking involve
Breaking covalent bonds in hydrocarbon molecules
What is used during cracking
A catalyst using aluminium
Which of the alkanes and alkenes are saturated and unsaturated
Alkanes are saturated and alkenes are unsaturated
Why is petrol used for cars
It is easily ignited, liquid at room temp and releases a large amount of energy during combustion
What can also be used to fuel cars
Hydrogen
How is this hydrogen produced
It is a by product of cracking or by reacting methane with steam
Why is hydrogen good for fuel
It produces no greenhouse gases, ignited easily and produces large amounts of energy in combustion
Why is hydrogen also bad
Because it’s a gas at room temp and is harder to store unless under high amounts of pressure
How does the worlds atmosphere composition change
By living organisms
What was the early atmosphere thought to be like
Mainly carbon dioxide with little of no oxygen
What helped form the early atmosphere
Volcanoes
Which other planets are made up of volcanoes
Venus and mars
What was another theory about the early atmosphere
That it was 98%+ nitrogen
How were the oceans formed
The earth cooled down and condensed all the water vapour
Why is there a lot of evidence that there was no oxygen in the early atmosphere
It’s not produced by volcanoes, and that iron pyrite is only formed with an absence of oxygen
How did oxygen levels start to rise
Once microorganisms were around they started to produce oxygen that oxidised iron in the sea. Once all the iron was oxidised oxygen could be released into the atmosphere
What is a hypothesis about the reducing levels of carbon dioxide
That it dissolved in the oceans and sea creatures used it t make shells
What was one of the earliest photosynthetic organisms
Cyanobacteria
What did this bacteria produce
Stromatolites as layers of sand and sediment from the shallow ocean got caught in the sticky mucus
What percentage of the earths atmosphere is oxygen
21%
What does the earth emit
Infrared waves
What is the greenhouse affect
When gases in the atmosphere trap infrared waves and send them back to earth
Name some greenhouse gases
Carbon dioxide, methane and water vapour
What is there a strong correlation between
CO2 levels and the surfaces temperature
What does this correlation not mean
That there is a casual link ( one causes another )
Why are modern thermometers better
Because they are less prone to error and have a greater resolution
What produces a lot of methane
Livestock and rice paddy fields, all due to bacteria
What will rising global temperatures cause
The poles to melt and for ocean levels to rise
What will move due to flooding
Animals, and they may not survive in their new habitats
What will happen to the weather during climate change
It will be more extreme like heavy rainfall and very hot summers
How does coral get bleached
When the seas temp rises which causes coral to push out photosynthetic algae that lives in its tissue
