Fractions
Give a use of bitumen
road surfaces
Which elements do hydrocarbons contain?
hydrogen and carbon ONLY
What were the main two gases in the Earth's early atmosphere?
carbon dioxide and water vapour
What happens to the sulfur found in fossil fuels when they are burnt?
It produces sulfur dioxide
Why do we need to come up with alternatives to fossil fuels? (two reasons)
They will run out
Burning them gives off CO2 which causes global warming
Which fraction is used for fuel for planes?
kerosene
What do we mean by the term "cracking"?
Breaking down larger hydrocarbons into more useful smaller hydrocarbons
Where did the main gases in the Earth's early atmosphere come from?
Volcanoes
What problem do both sulfur dioxide and nitrogen oxide cause?
acid rain
What are the products of complete combustion of hydrogen?
carbon dioxide and water
Give two uses of fuel oil
Fuel for ships
Fuel for power stations
Write down the formula for pentane.
C5H12
List the 3 main gases in the Earth's current atmosphere, in order of abundance
Nitrogen, oxygen, argon
Write a balanced symbol equation for the combustion of methane
CH4 + 2O2 → CO2 + 2H2O
Give an advantage of using hydrogen as a fuel compared to petrol
does not produce CO2 / greenhouse gases
won't run out / renewable
List all the fractions obtained from crude oil, in order of smallest to longest carbon chains
gases, petrol, kerosene, diesel, fuel oil, bitumen
How do we separate out the different fractions from crude oil?
fractional distillation
Where did the oxygen in the Earth's atmosphere come from?
Product of photosynthesis
Why is carbon monoxide toxic?
It prevents oxygen combining to red blood cells
Give a disadvantage of using hydrogen as a fuel for cars
difficult to store
highly flammable
can't see it
it's a gas not a liquid
Explain what happens to the boiling point of the fractions as you go higher up the fractionating column.
The boiling point decreases, as there are less intermolecular forces between the molecules, which take less energy to break
Why do we need to carry out "cracking"?
To match supply and demand for shorter length hydrocarbons
To provide feedstock for making plastics
Give two reasons for the decrease in the amount of carbon dioxide in the Earth's atmosphere
removed by photosynthesis
dissolved in the oceans
How are nitrogen oxides formed in the engines of cars?
oxygen and nitrogen from the air react due to the high temperatures in the engine
Give two ways that we could reduce the effects of climate change
plant forest / less deforestation
carbon capture
reflect sunlight into space
flood defences / dams
irrigation systems