- No. 9. Oxides of nitrogen cause air pollution. Describe the sources of these compounds.
Answer. Combustion of fossil fuels in internal combustion engines, in thermal power stations and factories where huge amount of coal is burnt, NO is formed by the direct combination of nitrogen and oxygen as shown in figure.
N2 + O2 2NO
However, it quickly reacts with air to form nitrogen dioxide. NO is highly toxic gas.
2NO + O2 2NO2
Nitrogen in the air is normally
Formation of NO & NO2 on combustion of fossil fuel and causing air
Mixture of these gases represented as NOX enter in the air through automobile exhaust and chimneys of thermal power station
and factories. It irritates breathing passage.
- No.10. What is the main cause of air pollution? Explain the role of Government to control the pollution.
Answer. Causing air pollution through auto exhaust is almost the most common air polluting act which an average driven commits daily for hours without considering its consequences. One is poisoning the air, creating a big problem that has local, regional and global effects.
Government should do short term as well as long term planning to preserve the natural world. Because without a healthy natural environment, there will be no healthy human, plant, or animal.
(i) First of .all quality of fuel must be improved by adding anti-knocking agents in fuels. At the same time, automobiles combustion engines must be efficient so that they should burn the fuel completely. No unburned hydrocarbon molecules (fuel) should come out of the exhaust. The hydrocarbons present in polluted air are very harmful They can cause liver damage and even cancer. So government must guide the people to use converters in auto exhausts.
(ii) Fossil fuels produce a number of air pollutants because of impurities and complex molecule nature of hydrocarbons. Government should promote the use of alternative fuels such as methanol, ethanol and bio-diesel. These fuels are less polluting than hydrocarbons fuel, as their molecules are simple, and burn completely in the engine. Their burning produces less carbon monoxide, soot and other pollutants”
(iii) The government must plan to avoid using carbon dioxide producing fuels as it is a greenhouse gas. It should go to battery-powered electric vehicles.
(iv) Government should provide efficient transport in the big cities, so that people should avoid using their own vehicles.