1. The main industrial origin of sulphur dioxide is the burning of fossil fuels, particularly coal and petroleum. Particularly in the burning of coal, the problem arises due to these fuels containing some compounds of sulphur as impurities. When these fuels are burnt, the sulphur is oxidised to produce sulphur dioxide:
4DeS29s0 + 11O2(g) -> 2Fe2O3(s) + 8SO2(g)
SO2 is the major contributor to acid rain that can affect places thousands of kilometres from the source. Sulfur can be removed from coal during the burning process by using limestone and can also be removed from fossil fuels prior to burning the fuel. This prevents the formation of SO2.
It can also come from the smelting of sulphide ores. For example, the smelting plant releasing Sulfur dioxide into the atmosphere is the roasting of chalcopyrite in the extraction of copper:
2CuFeS2(s) + 5O2(g) + 2SiO2(s) -> 2Cu(l) + 4SO2(g) + 2FeSiO3(l)
b) Nitrogen oxides greatly contribute to the acidic oxide pollutants in the atmosphere mainly de to the internal combustion of engines. Nitrogen oxides are formed in car engines and other high-temperature combustion environments because the high temperatures cause nitrogen and oxygen in the air to react:
N2(g) + O2(g) -> 2NO(g)
2NO(g) + O2(g) -> 2NO2(g)
Nitrogen oxides contribute to the formation of photochemical smog and acid rain.
C) The release of gases such as sulphur dioxide and nitrogen oxides in the environment arouses many reasons for concerns. Sulfur dioxides come naturally from volcanoes, bushfires and the decomposition of organic material. They come industrially from the burning of coal and the smelting of lead and copper. Sulfur dioxide and trioxide are highly irritating gases which present major health risk, especially for people suffering from asthma and other respiratory disorders. For example, the London smogs in the 1950’s resulted in many deaths.
When sulfur dioxides enter the atmosphere they may dissolve to produce acid rain. Acid rain then...