COAL AND PETROLEUM. 1. What are Inexhaustible and Exhaustible Natural Resources? Answer: Inexhaustible Natural Resources:

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1 COAL AND PETROLEUM Main Concepts and Results: Coal, petroleum and natural gas are fossil fuels. Fossil fuels were formed from the dead remains of living organisms millions of years ago. Fossil fuels are exhaustible resources. Coke, coal tar and coal gas are the products of coal. Petroleum gas, petrol, diesel, kerosene, paraffin wax, lubricating oil are obtained by refining petroleum. Coal and petroleum resources are limited. We should use them judiciously. Exercise: 1. What are Inexhaustible and Exhaustible Natural Resources? Answer: Inexhaustible Natural Resources: These resources are present in unlimited quantity in nature and are not likely to be exhausted by human activities. Examples are: sunlight, air. Exhaustible Natural Resources: The amount of these resources in nature is limited. They can be exhausted by human activities. Examples of these resources are forests, wildlife, minerals, coal, petroleum, natural gas etc. 2. Where do we get coal from and how is it formed? Answer: About 300 million years ago the earth had dense forests in low lying wetland areas. Due to natural processes, like flooding, these forests got buried under the soil. As more soil deposited over them, they were compressed. The temperature also rose as they sank deeper and deeper. Under high pressure and high temperature, dead plants got slowly converted to coal. As coal contains mainly carbon, the slow process of conversion of dead vegetation into coal is called carbonisation. 3. What is Coke?

2 Answer: Coke 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. 4. What is coal tar? Answer: It is a black, thick liquid with unpleasant smell. It is a mixture of about 200 substances. Products obtained from coal tar are used as starting materials for manufacturing various substances used in everyday life and in industry, like synthetic dyes, drugs, explosives, perfumes, plastics, paints, photographic materials, roofing materials, etc. Interestingly, naphthalene balls used to repel moths and other insects are also obtained from coal tar. 5. What is Bitumen? Answer: Bitumen, a petroleum product, is used in place of coal-tar for metalling the roads. 6. What is coal gas? Answer: 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. 7. What is petroleum? Answer: Petroleum is a natural resource from which petrol and diesel are obtained. 8. How was petroleum formed? Answer: Petroleum was formed from organisms living in the sea. As these organisms died, their bodies settled at the bottom of the sea and got covered with layers of sand and clay. Over millions of years, absence of air, high temperature and high pressure transformed the dead organisms into petroleum and natural gas. Fig. 1 shows the deposits of petroleum and natural gas.

3 Fig.1 Petroleum and natural gas deposits 9. Where and when was world s first oil well drilled? Answer : The world s first oil well was drilled in Pennsylvania, USA, in Eight years later, in 1867, oil was stuck at Makum in Assam. 10. Name some regions of India where oil is found? Answer : In India, oil is found in Assam, Gujarat, Mumbai High and in the river basins of Godavari and Krishna. 11. What is petroleum refining? Answer : Petroleum is a dark oily liquid. It has an unpleasant odour. It is a mixture of various constituents such as petroleum gas, petrol, diesel, lubricating oil, paraffin wax, etc. The process of separating the various constituents/ fractions of petroleum is known as refining. It is carried out in a petroleum refinery. 12. What are petrochemicals? Answer : Many useful substances are obtained from petroleum and natural gas. These are termed as Petrochemicals. These 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).

4 13. Write down various constituents of petroleum and their uses. Answer : Various constituents of petroleum and their uses 14. What is black gold? Answer : Due to its great commercial importance, petroleum is also called black gold. 15. Write a short note on Natural gas? Answer : Natural gas is a very important fossil fuel because it is easy to transport through pipes. Natural gas is stored under high pressure as compressed natural gas (CNG). CNG is used for power generation. It is now being used as a fuel for transport vehicles because it is less polluting. It is a cleaner fuel. The great advantage of CNG is that it can be used directly for burning in homes and factories where it can be supplied through pipes. Such a network of pipelines exists in Vadodara (Gujarat), some parts of Delhi and other places. Natural gas is also used as a starting material for the manufacture of a number of chemicals and fertilisers. India has vast reserves of natural gas. In our country, natural gas has been found in Tripura, Rajasthan, Maharashtra and in the Krishna Godavari delta. 16. Can coal, petroleum and natural gas be prepared in the laboratory from dead organisms? Answer: No. Their formation is a very slow process and conditions for their formation cannot be created in the laboratory.

5 MULTIPLE CHOICE QUESTIONS 1. Various materials which are obtained from nature are called natural resources. Which of the following is not a natural resource? (a) minerals (c) soil (b) water (d) plastic 2. Air is a natural resource and cannot be exhausted by human activities. It is known as inexhaustible natural resource. Which of the following is another inexhaustible natural resource? (a) coal (c) sun-light (b) petroleum (d) minerals 3. Which of the following is a pair of exhaustible natural resources. (a) coal and soil (c) water and petroleum (b) air and sun-light (d) wild life and mineral 4. Coal is processed in industries to get some useful products. Which of the following is not obtained from coal? (a) coke (c) coal gas (b) coal tar (d) CNG 5. Exhaustible natural resources are: (a) unlimited in quantity. (b) not dependent on nature. (c) limited in quantity. (d) not exhausted by human activities. 6. Fossil fuels are obtained from: (a) remains of non-living materials. (b) dead remains of birds only. (c) dead remains of insects only. (d) dead remains of living organisms. 7. Coal is formed from the remains of (a) vegetation only (c) both vegetation and animals (b) animals only (d) neither vegetation nor animals 8. Which substance is formed by the carbonisation of dead vegetation?. (a) coal (c) coal gas (b) coke (d) coal tar 9. Naphthalene balls are obtained from coal tar and are used as (a) mosquito repellant (c) moth repellant (b) honey bee repellant (d) snake repellent 10. Which of the following is not a constituent of petroleum? (a) paraffin wax (c) petrol (b) lubricating oil (d) coke

6 11. Petroleum was formed from organisms: (a) living on the land (c) living in the sea (b) living on the plants (d) living on the rocks 12. Choose the correct statement from the following: (a) It is difficult to transport natural gas through pipes. (b) The disadvantage of natural gas is that it can not be used directly for burning in homes. (c) Natural gas is stored under high pressure as compressed natural gas. (d) Natural gas cannot be used for power generation. Answer: 1. d 2. c 3. d 4. d VERY SHORT ANSWER QUESTIONS 5. c 6. d 7. A 8. a 9. c 10. d 11. c 12. C 13. You are provided with a mixture of petroleum and water. Can you suggest a method to separate the two? Answer: Decantation. 14. What does CNG stand for and why is it considered to be a better fuel than petrol? Answer: CNG stands for Compressed Natural Gas. It is considered to be a better fuel because it is less polluting. 15. Name the petroleum product used as fuel for stoves, lamps and jet aircrafts. Answer: Kerosene is used as fuel for stoves, lamps and jet aircrafts. 16. Fill in the blanks in the following sentences. (a) Coal is one of the used to cook food. (b) When heated in air, coal burns and produces mainly gas. (c) Coal tar is a black, thick with an smell. (d) Petroleum, and are fossil fuels. (e) Forests and coal are natural resources. Answers: (a) fuels (b) carbon dioxide (c) liquid, unpleasant (d) coal, natural gas (e) exhaustible 17. The underlined words in the following sentences have been jumbled up. Write them in their correct form. (a) Loca is obtained from mines.

7 (b) Umpetlore is a fossil fuel. (c) Rineryfe is a place where various fractions of peroleum are separated. (d) Keenrose is a fuel used in jet crafts. (e) Nutsgilh is an example of inexhaustible natural resources. Answers: (a) coal (b) petroleum (c) refinery (d) kerosene (e) sunlight 18. Fill in the blanks. (a) The slow process of conversion of dead vegetation into coal is called. (b) Coal and petroleum are formed from the dead remains of organisms and are known as. (c) The black thick liquid with smell is known as coal tar. (d) During the processing of coal to get coke, coal tar and are also obtained. (e) The process of separating the various constituents of petroleum is known as. (f) Excessive burning of fossil fuels is a major cause of. Answers: (a) carbonisation, (b) fossil fuels, (c) unpleasant, (d) coal gas, (e) refining, (f) air pollution. 19. Write True/False against the following statements. (a) Oxygen in air is an exhaustible natural resource. (b) Resources which are present in unlimited quantity in nature are called exhaustible natural resources. (c) Wildlife is an exhaustible natural resource. (d) Under high temperature and pressure, dead plants get slowly converted to coal. (e) CNG is less polluting fuel than petrol and diesel. Answers: (a) False, (b) False, (c) True, (d) True, (e) True.