Coal and Petroleum

Q23. Write full form of LPG and CNG.

Ans. LPG – Liquefied Petroleum Gas

CNG – Compressed natural gas

Q24. Which fuel is used in light automobiles such as motor cycles/ scooters and cars?

Ans. Petrol is used as a fuel in light automobiles such as motor cycles/ scooters and cars.

Q25. What are ‘Petrochemicals’?

Ans. Many useful substances are obtained from petroleum and natural gas. These are termed as ‘Petrochemicals’.

Q26. What is carbonization?
Or
Why is process of formation of coal called carbonization?

Ans. As coal contains mainly carbon, the slow process of conversion of dead vegetation into coal is called carbonisation.

Q27. Why the layer containing petroleum and gas is above the water?

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.

Q28. What is meant by refining of petroleum and where is it done?

Ans. The process of separating the various constituents/fractions of petroleum is known as refining. It is carried out in a petroleum refinery.

Q29. Name the agency in India who advises people how to save petrol/diesel.

Ans. In India, the Petroleum Conservation Research Association (PCRA) advises people how to save petrol/diesel while driving.

Q30. How is coal gas obtained? Write its uses.

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.

Q31. Describe characteristics and uses of coke.

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.

Q32. Write the characteristics of coal tar.

Ans. Characteristics of coal tar

                         i.        It is a black, thick liquid with unpleasant smell.

                        ii.        It is a mixture of about 200 substances.

Q33. What are the uses of CNG?

Ans. Uses

                          i.        It is used for power generation.

                         ii.        It is now being used as a fuel for transport vehicles.

Q34. Give two disadvantages of using fossil fuels.
Or
What are the main disadvantages of fossil fuels?

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.

Q35. What are the uses of petrochemicals?
Or
Give the uses of petrochemicals obtained from petroleum.

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).

Q36. What is the use of natural gas?

Ans. Uses

                         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.

Q37. Explain why fossil fuels are exhaustible natural resources.

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.

Q38. Why should the fossil fuels be used with care?
Or
Why should fossil fuel be used carefully?
Or
Why should we use fossil fuels economically and wisely?

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.