Ans. LPG – Liquefied Petroleum Gas
CNG – Compressed natural gas
Ans. Petrol is used as a fuel in light automobiles such as motor cycles/ scooters and cars.
Ans. Many useful substances are obtained from petroleum and natural gas. These are termed as ‘Petrochemicals’.
Ans. As coal contains mainly carbon, the slow process of conversion of dead vegetation into coal is called carbonisation.
Ans. The layer containing petroleum and gas is above the water because oil and gas are lighter than water and do not mix with it.
Ans. The process of separating the various constituents/fractions of petroleum is known as refining. It is carried out in a petroleum refinery.
Ans. In India, the Petroleum Conservation Research Association (PCRA) advises people how to save petrol/diesel while driving.
Ans. Coal gas is obtained during the processing of coal to get coke. It is used as a fuel in many industries situated near the coal processing plants.
Ans. It is a tough, porous and black substance. It is almost pure form of carbon. Coke is used in the manufacture of steel and in the extraction of many metals.
Ans. Characteristics of coal tar
i. It is a black, thick liquid with unpleasant smell.
ii. It is a mixture of about 200 substances.
i. It is used for power generation.
ii. It is now being used as a fuel for transport vehicles.
Ans. Disadvantages of using fossil fuels
i. Burning of these fuels is a major cause of air pollution.
ii. Their use is also linked to global warming.
Ans. Petrochemicals are used in the manufacture of detergents, fibres (polyester, nylon, acrylic etc.), polythene and other man-made plastics. Hydrogen gas obtained from natural gas, is used in the production of fertilisers (urea).
i. It is used as fuel.
ii. It is also used as a starting material for the manufacture of a number of chemicals and fertilisers.
Ans. Fossil fuels are exhaustible natural resources because it required the dead organisms millions of years to get converted into these fuels. On the other hand, the known reserves of these will last almost a few hundred years.
Ans. Burning of these fuels is a major cause of air pollution. Their use is also linked to global warming. It is therefore necessary that we use these fuels only when absolutely necessary. This will result in better environment, smaller risk of global warming and their availability for a longer period of time.
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