Class 8 Science

Coal and Petroleum

NCERT Solution

Question 1: What are the advantages of using CNG and LPG as fuels?

Answer: Following are the advantages of using CNG and LPG as fuels:

Question 2: Name the petroleum product used for surfacing of roads.

Answer: Bitumen

Question 3: Describe how coal is formed from dead vegetation. What is this process called?

Answer: Dead remains of plants got buried under the earth millions of years ago. Due to intense heat and pressure inside the earth they got converted into coal. The process of conversion of dead remains of plants into coal is called carbonization.

Question 4: Fill in the blanks:

  1. Fossil fuels are…………, ………….. and ………………….
  2. Process of separation of different constituents from petroleum is called ……………..
  3. Least polluting fuel for vehicle is …………………….

Answer: (a) coal, petroleum, natural gas, (b) Refining, (c) CNG

Question 5: Tick True/False against the following statements:

  1. Fossil fuels can be made in the laboratory.
  2. CNG is more polluting fuel than petrol.
  3. Coke is almost pure form of carbon.
  4. Coal tar is a mixture of various substances.
  5. Kerosene is not a fossil fuel.

Answer: (a) F, (b) F, (c) T, (d) T, (e) F

Question 6: Explain why fossil fuels are exhaustible natural resources.

Answer: It takes millions of years for the formation of fossil fuels. The rate at which we are using them is very fast compared to the rate of their formation. Due to this, fossil fuels are exhaustible in nature.

Question 7: Describe characteristics and uses of coke.

Answer: Coke is a type of coal. It is a tough, porous and black substance. It is almost pure form of carbon. Coke burns much cleaner than coal and provides more energy for comparable mass. It is used in manufacture of steel and in extraction of many minerals.

Question 8: Explain the process of formation of petroleum.

Answer: The organisms which lived in the sea got buried at the bottom of oceans. Over a period of time, their dead bodies were covered with sediments. Intense pressure and heat under the earth’s layers transformed these organisms into petroleum.

Question 9: The following Table shows the total power shortage in India from 2004 to 2010. Show the data in the form of a graph. Plot shortage percentage for the years on the Y-axis and the year on the X-axis.

YearShortage %


graph of data on power shortage in India