1. Consequences of using fossil fuels
Wong Yu
Tso Yat Long
Wong Mei Sze
Ho Kin Fung

2. Consequences of using fossil fuels
Fossil fuels create environmental problems resulting from:
Extraction and processing
Transportation and storage
Combustion

3. Air pollution
Major sources of air pollutants are:
Exhaust of motor vehicles
Power plants
Factories
Incinerators

4. Air pollution
Main air pollutants include:
Carbon monoxide, forms when fossil fuels are burnt incompletely.
CxHy + O2  CO H2O + CO + C
Sulphur dioxide, most fossil fuels contain sulphur. When they are burnt, they give out sulphur dioxide.
[S] SO2  CO2
Nitrogen oxides, include nitrogen monoxide and nitrogen dioxide, produced when fossil fuels are burnt at high temperature.

5. Air pollution
Unburnt hydrocarbons, from motor vehicles, it irritate our respiratory system.
Suspended particulates, small solid particles that remain suspended in air for a long time.

6. Acid rain
Rainwater is naturally acidic, with a pH of about 5.6. This is because CO2 in the air dissolves in rainwater to form carbonic acid.
CO H2O  H2CO3
However, Rainwater with pH less than 5.6 is called acid rain, because sulphur dioxide and nitrogen oxides dissolve in rainwater to form sulphurous acid and nitrous acid SO H2O  H2SO3
Some acids further reacts with oxygen to form sulphuric acid and nitric acid.
H2SO [O]  H2SO4

7. Harmful effects of acid rain
Damaging plants, acid rain make the soil acidic, many plants cannot grow well in acidic soil. Also, leaves are damaged by acid, plants will die as photosynthesis cannot take place.
Killing aquatic life, Fish and water plants cannnot survive in water which is too acidic.

8. Corroding metal objects, metal fences, bridges and car bodies, even underground metal pipelines, will be corroded by acid rain.
Fe + 2H+  Fe H2
Corroding building materials, acid rain will corrode materials including limestone, marble, sandstone, cement and concrete. The calcium carbonate in these materials will be dissolved by acid.
CaCO H+  Ca CO2 + H2O

9. Possible ways to reduce the formation of acid rain
To control acid rain, we must reduce the emission of acidic pollutants. Possible ways are:
Installing catalytic converters in motor vehicles
Using LPG instead of diesel oil
Using fuels of low sulphur content in factories
Using scrubbers and flue gas desulphurization system