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GCSE Chemistry C1
Transcript of GCSE Chemistry C1
The atmosphere today
Air pollution-Nitrogen Phase 2
(the next 2 billion years) Phase 1
(the first 2 billion years)
Volcanoes gave out gases
-Nitrogen Oceans were formed when the
water vapour cooled. The Evolution Of The Atmosphere Green plants evolved and produced oxygen.
They removed CO2 and produced O2 by photosynthesis.
When the plants died the carbon they had removed became sedimentary rock and fossil fuels. Phase 3
(4 billion years up to present day) -Complex organisms evolved
-The increase of oxygen in the atmosphere, killed off many early organisms allowing more complex ones to develop. The Atmosphere Today -The earth is surrounded by a mixture of gases, the atmosphere. The atmosphere is made from 3 main gases:
Argon 1% -Human activity is changing the atmosphere.
-Small amounts of pollutants are being added to the air.
5 of the main pollutants are:
1) Carbon dioxide
2) Carbon monoxide
3) Particulates (Carbon)
4) Sulfur dioxide
5) Nitrogen oxides These pollutants come from many different sources.
They can come from burning fuels in Power stations and vehicles or even from nature-volcanoes.
Some gases are directly harmful to humans
(carbon monoxide reduces the amount of oxygen carried by the blood)
Some harm us indirectly by damaging the enviroment
(carbon dioxide causes climate change) Fossil fuels The majority of the fuels that we use contain 2 elements carbon and hydrogen, also known as hydrocarbons.
Most hydrocarbons are fossil fuels which were dead plants and animals that have been compacted over millions of years.
The difference between petrol, diesel fuel and fuel oil is that their hydrocarbons vary in size.
Coal however is not a hydrocarbon. It is mostly made of carbon with other impurities added. Burning fuel is an example of oxidation(chemical reaction) Any reaction where oxygen is added is called an oxidation reaction. Any reaction where oxygen is lost is called a reduction reaction. The resulting carbon based products often pollute the atmosphere. Carbon dioxide
(CO2) Carbon monoxide
(CO) Particulate Carbon Carbon dioxide will stay in the atmosphere causing problems until it is removed.
-It can be removed naturally (photosynthesis).
-It will dissolve in rain water, lakes, seas and rivers.
BUT...... The increase level of production from human activity causes the green house effect wich is warming up the earth Produced is there isn't enough oxygen when fuel is burnt.
The problem with this is that it is poisonous to humans when inhaled. This is essentially soot, small bits of carbon that cause buildings to go black.
If inhaled can cause breathing problems. Air pollution sulfur/nitrogen Sulfur pollution comes from impurities in the fuel.
When the fuel burns the sulfur burns too, forming the pollutant sulfur dioxide(SO2), which usually ends up in the atmosphere.
The only way it can leave the atmosphere is in the form of acid rain, which is not good for the environment. Nitrogen pollution doesn't come from the fuel itself but from the air around it.
When fossil fuels burn at such high temperatures nitrogen in the air reacts with the oxygen in the air to produce small amounts of nitrogen oxides. This happens in car engines.
Nitrogen monoxide(NO) and nitrogen dioxide(NO2) produce acid rain in the same way sulfur dioxide does. We can Reduce pollution From power stations From our cars We can do this by
A)Taking the sulfur out of natural gas and fuel oil so that there is less sulfur dioxide.
B)In coal burning power stations they can clean the gases as they pass through the chimney.
C)Find alternative energy sources. Cars now have more efficient engines.
Low sulfur fuel is now available for cars.
Many cars now have catalytic converters which changes nitrogen monoxide to harmless nirtogen and oxygen.
There is a legal limit on polluting emissions from cars checked annualy on the M.O.T test.