10. Chemistry Of The Enviroment

78% Nitrogen 21% Oxygen 1% other variable gases (0.9% Argon, 0.04% CO2)

Gases that cannot be liquefied by pressure alone at normal temperatures Oxygen and nitrogen

To separate oxygen from liquified air

To separate oxygen from liquid air

Their concentration varies according to place and time Argon (0.9%), CO2(0.04%), Nitrogen oxides, Helium, hydrogen, methane, neon

Fractional distillation of air

P\producing gases by separating oxygen from liquid air

Pure air is liquified under high pressure and low temperatures (-200*) Purified air contains nitrogen, argon and oxygen Temperature is increased causing nitrogen to vapourise first, argon second and oxygen third

Nitrogen- fertilizers Argon - lightbulbs Oxygen - makes steel for welding

When some of the thermal energy from the sun is absorbed by greenhouse gases and is re-emitted in all directions reducing the amount of energy lost into space as it is trapped within the earths atmosphere causing global warming

Suns thermal energy enters earths atmosphere where some is reflected back from earths surface but most is absorbed and re-emmited back from earth into space. Some of the thermal energy from the sun is absorbed by greenhouse gases and re-emitted in all directions. (Greenhoiuse effect) This reduces the amount of energy lost into space and traps it within the earths atmosphere causing global temperature to rise(Global Warming)

Carbon dioxide Particulates Oxides of nitrogen Sulfur oxides Methane Carbon monoxide

Combustion of fossil fuels containing sulfur (at power stations)

Exposure cuases respiratory problems Forms acid rain when dissolved in water-corrodes buildings + reduces productivity of soil+increases acidity of lakes

Using low sulfur fules and flue gas desulfurisation

Calcium oxide being added to neutralise sulfur dioxide

Complete combustion of carbon containing fuels such as methane

Higher levels of carbon dioxide lead to increased global warming which lead to climate change

Incomplete combustion of carbon containing fuels such as there being limited oxygen when petrol is being burned in a car cylinder

Toxic as it combines with haemoglobin in blood and prevents it from carrying oxygen

Catalytic converters in cars prevent carbon monoxide from forming

Incomplete combustion of carbon containing fuels (fossil fuels) can produce particulates of carbon (soot) Incomplete combustion of methane can cause carbon monoxide and carbon

Respiratory problems and cancer

Formed in car engine cylinders when oxygen and nitrogen from the air react at high temperatures and in the atmosphere during lightning storms