Worksheet – FULL Answers (Step-by-Step)

Class: 8 | Science

Chapter 5: Coal and Petroleum

A. Very Short Answer Questions (VSA)

1. What are fossil fuels?
   Fossil fuels are fuels formed from the remains of plants and animals buried under the earth for millions of years.
2. Name one solid fossil fuel.
   Coal.
3. What is coke?
   Coke is a tough, porous, black substance and a pure form of carbon.
4. Which fuel is called the cleanest fossil fuel?
   Compressed Natural Gas (CNG).
5. Name one product obtained from petroleum.
   Petrol.

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B. Short Answer Questions (SA)

1. Why are fossil fuels called non-renewable?
   Fossil fuels take millions of years to form and are available in limited quantities. Once used, they cannot be replaced quickly.
2. What are the main products obtained from coal?
   Coke, coal tar, and coal gas.
3. Why is CNG preferred over petrol and diesel?
   CNG produces less pollution, gives more energy, and leaves no residue.
4. What is petroleum refining?
   Petroleum refining is the process of separating crude oil into useful components called fractions.
5. Write two uses of coal tar.
   (i) Making roads
   (ii) Manufacturing dyes and chemicals

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C. Long Answer Questions (LA)

1. Explain the formation of fossil fuels.
   Millions of years ago, plants and animals died and got buried under layers of soil. Due to high pressure and temperature, they slowly converted into coal, petroleum, and natural gas.
2. Describe the process of refining petroleum.
   Crude oil is heated in a refinery. Different fractions separate at different temperatures and are collected separately.
3. Explain the uses of coke, coal tar, and coal gas.
   Coke: Used as fuel and in steel making.
   Coal tar: Used in roads, medicines, dyes.
   Coal gas: Used as fuel.
4. Why should we conserve fossil fuels?
   Fossil fuels are limited and cause pollution. Conserving them helps protect the environment and ensures availability for future generations.

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D. Fill in the Blanks

1. Coal is a solid fossil fuel.
2. Petroleum is also called black gold.
3. CNG gas is used as a fuel in homes and vehicles.
4. Coal tar is used for making roads.

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E. True or False

1. Petroleum is a renewable resource – False
2. Coke is a pure form of carbon – True
3. Natural gas produces less pollution – True
4. Coal gas is obtained during the processing of coal – True