Coal and Petroleum

Natural resources are of two kinds: inexhaustible resources, such as sunlight and air, which are present in unlimited quantity, and exhaustible resources, such as forests, minerals, coal, petroleum and natural gas, which can be used up by human activities. In this chapter you will learn how coal was formed about 300 million years ago, when dense forests in low-lying wetlands were buried under soil and slowly converted into coal under high pressure and temperature, a process called carbonisation. When coal is processed in industry, it gives useful products: coke, an almost pure form of carbon used in making steel; coal tar, from which dyes, drugs, explosives, paints and naphthalene balls are made; and coal gas. You will also study petroleum and natural gas, formed from organisms that lived in the sea. Petroleum is refined into LPG, petrol, kerosene, diesel, lubricating oil, paraffin wax and bitumen. Because these fossil fuels are limited and pollute the air, you will learn PCRA tips for saving petrol and diesel.

Detailed Worksheet: Coal and Petroleum Section A - Definitions (10 marks) 1. Distinguish between exhaustible and inexhaustible natural resources, giving two examples of each. (2 marks) 2. What are fossil fuels? Why are coal, petroleum and natural gas given this name? (2 marks) 3. What is carbonisation? Why is coal said to be formed by carbonisation? (2 marks) 4. Define coke, coal tar and coal gas, and state one use of each. (2 marks) 5. What is meant by the refining of petroleum? Why is petroleum called "black gold"? (2 marks) Section B - Calculations and Applications (15 marks) 6. Write one use of each of the following products of petroleum refining: LPG, petrol, kerosene, diesel, lubricating oil, paraffin wax and bitumen. (3 marks) 7. A car runs 15 km on one litre of petrol when driven at a steady moderate speed on a highway, but only 11 km per litre in city traffic with frequent braking. Find the petrol needed for a journey of 330 km in each case, and the money saved by steady driving if petrol costs Rs 100 per litre. (3 marks) 8. A country has oil reserves of 600 million tonnes and uses 30 million tonnes every year. (i) For how many years will the reserves last at this rate? (ii) If yearly use increases by 50%, how long will they last? (iii) What does this show about exhaustible resources? (3 marks) 9. Arrange these events in chronological order and find the gap in years between the first oil well in the world and the discovery of oil in India: coal gas used for street lighting in New York (1820), first oil well drilled in Pennsylvania, USA (1859), coal gas first used for street lighting in London (1810), oil struck at Makum in Assam (1867). (3 marks) 10. Give three advantages of CNG as a fuel for vehicles. Name two places in India where natural gas is found. A city runs 300 CNG buses, each using 20 kg of CNG a day; find the total CNG used in a day. (3 marks) Section C - Diagrams (10 marks) 11. Draw a flowchart showing the stages in the formation of coal from forests buried in wetlands, and label the conditions (pressure, temperature and absence of air) under which carbonisation takes place. (4 marks) 12. Draw a labelled diagram showing a deposit of petroleum and natural gas under the sea bed, with the layers of rock, gas, oil and water, and a drilled oil well. (3 marks) 13. Draw a labelled diagram or flowchart showing crude oil being separated in a refinery into petroleum gas, petrol, kerosene, diesel, lubricating oil, paraffin wax and bitumen. (3 marks) Section D - Analysis and Higher-order Thinking (15 marks) 14. Fossil fuels took millions of years to form, but we are using them up in a few hundred years. Explain why they are called exhaustible resources, describe two consequences of their rapid use, and suggest two alternative sources of energy. (5 marks) 15. The Petroleum Conservation Research Association (PCRA) advises drivers to drive at a constant and moderate speed, switch off the engine at traffic lights, keep the correct tyre pressure and have the vehicle serviced regularly. Explain how each of these tips saves fuel. (5 marks) 16. Explain why coke is preferred over coal for making steel and as a fuel in industry. List five products obtained from coal tar. Explain how the burning of coal and petroleum products adds to air pollution and global warming. (5 marks) Instructions: Time allowed 2 hours. Attempt all sections. Draw all flowcharts and diagrams neatly in pencil and label every part.