C9 Air Pollution (page 160) Flashcards
Increasing Carbon dioxide is causing climate change. But CO2 isn’t the only gas released when fossilf fuels burn, what are the?
oxides of nitrogen
sulfur dioxide
carbon monoxide
Fossil fuels, such as crude oil and coal, contain what?
hydrocarbons.(these are compounds that only contain hydrogen and carbon (see page 50)).
During combustion, the carbon and hydrogen in these compounds are oxidised so that carbon dioxide and water vapour are released into the atmosphere.
When there’s plenty of oxygen, all the fuel burns, what is this called?
complete combustion
It there’s not enough oxygen, some of the fuel doesn’t burn - what is this called?
imcomplete combustion.
What do incomplete combustion not burn?
if there is not enough oxygen some of the fuel doesn’t burn (incomplete combustion), Under these conditions, solid particles (called particulates) of soot (carbon) and unburnt fuel are released and carbon monoxide can be produced as well as carbon dioxide.
Particulates in the air can cause all sorts of problems, explain why?
If particulates are inhaled, they can get stuck in the lungs and cause damage. This can then lead to respiratory problems.
They’re also bad for the environment - they themselves, or the clouds they help to produce, reflect sunlight back into space. This eans that less light reaches the Earth - causing global dimming.
It is not just particulate from incomplete combustion that cause problems. Carbon monoxide is pretty nasty too, explain why?
Carbon monoxide (CO) is really dangerouse because it can stop your blood from doing its proper job of carrying oxygen around the body.
It does this by binding to the haemoglobin in your blood that normally carries O2 - so less oxygen is able to be transported round your body.
A lack of oxygen in the blood can lead to fainting, a coma or even death.
Carbon monoxide doesn’t have any colour smell, so it’s very hard to detect. This makes it even more dangerous.
What can be released during the combustion of fossil fuels, such as coal, that contain sulfur impurities - the sulfur in the fuel becomes oxidised.
Sulfur Dioxide (SO2) is released during the combustion of fossil fuels.
How is Nitrogen Oxides created from a reaction between the nitrogen and oxygen in the air?
its caused by the heat of the burning (this can happen in the internal combustion engines of cars).
When these gasses mix with clouds they form dilute sulfuric acid or dilute nitric acid. This then falls as acid rain.
What do Acid Rain kill?
it kills plans and daages buildings and statues. It also makes metal corrode.
Sulfur dioxide and nitrogen oxides can also be bad for human health, why?
they cause respiratory problems if they’re breathed in.
How can you test for sulfur impurities in a fuel?
SO2 gas reacts with water to form sulfuric acid. You can test for sulfur impurities in a fuel by bubbling the gasses from combustion through a solution containing universal indicator - if the fuel contains sulfur, the gasses will contain SO2 which will form sulfuric acid and turn the universal indicator red.
Name three potential pollutants that could be released as a result of incomplete combustion of hydrocarbons, that wouldn’t be released as a result of a complete combustion? (3 marks)
E.g. particulates (soot) 1 mark.
unburnt fuels - 1 mark
carbon monoxide - 1 mark
