Coal and Petroleum class 8 questions and answers: Science Class 8 chapter 3 question answer
| Textbook | Ncert |
| Class | Class 8 |
| Subject | Science |
| Chapter | Chapter 3 |
| Chapter Name | Coal and Petroleum ncert solutions |
| Category | Ncert Solutions |
| Medium | English |
Are you looking for Class 8 Science chapter 3 question answer? Now you can download ncert solutions for class 8 science chapter 3 pdf from here.
Question 1: What are the advantages of using CNG and LPG as fuels?
Answer 1: The advantages of using CNG (Compressed Natural Gas) and LPG (Liquefied Petroleum Gas) as fuels are:
- Safety – CNG and LPG are stored in strong, sealed tanks, making them safer in case of leaks.
- Eco-friendly – They produce lower emissions compared to petrol and diesel, reducing air pollution.
- Cost-effective – Both fuels are cheaper than conventional fuels, leading to lower running costs.
- Higher Efficiency – CNG and LPG have higher calorific values, providing better fuel efficiency.
- Reduced Engine Wear – They burn cleaner, reducing carbon deposits and extending engine life.
Question 2: Name the petroleum product used for surfacing of roads.
Answer 2: Bitumen is used for surfacing of roads.
Question 3: Describe how coal is formed from dead vegetation. What is this process called?
Answer 3: Millions of years ago, trees, plants, ferns and forests got buried below the rocks, soil and sand due to natural processes like flooding, earthquake, etc. Slowly, as more soil deposited over them, they were compressed. This led to the conditions of high pressure and heat. These conditions along with the anaerobic conditions turned the carbon-enriched organic matter of wood into coal.
Question 4: Fill in the blanks.
(a) Fossil fuels are _______ , _______ and _______.
(b) Process of separation of different constituents from petroleum is called _______.
(c) Least polluting fuel for vehicle is _______.
Answer 4: (a) Fossil fuels Coal, Petroleum, and natural gas.
(b) The process of separation of different constituents from petroleum is called refining.
(c) The least polluting fuel for a vehicle is Compressed Natural Gas (CNG).
Question 5: Tick True/False against the following statements.
(a) Fossil fuels can be made in the laboratory. (T/F)
(b) CNG is more polluting fuel than petrol. (T/F)
(c) Coke is almost pure form of carbon. (T/F)
(d) Coal tar is a mixture of various substances. (T/F)
(e) Kerosene is not a fossil fuel. (T/F)
Answer 5:
(a) False
(b) False
(c) True
(d) True
(e) False
Question 6: Explain why fossil fuels are exhaustible natural resources.
Answer 6: Mineral oil is made from the dead remains of plants and animals that were buried in the ground millions of years ago under high temperatures and pressure, which cannot be synthesized in the laboratory. Therefore, fossil fuels are a completely natural resource.
Question 7: Describe characteristics and uses of coke.
Answer 7:
- Characteristics:
- i) Coke is tough.
- ii) Coke is porous.
- iii) Coke is black in colour.
- Uses:
- i) In the manufacture of steel.
- ii) In the extraction of metals (as a reducing agent).
Question 8: Explain the process of formation of petroleum.
Answer 8: Petroleum was formed from dead organisms that got buried in the sea millions of years ago. These dead bodies got covered with layers of sand and clay. Lack of air, high temperature, and high pressure transformed these dead organisms into petroleum and natural gas.
Question 9: The following Table shows the total power shortage in India from 1991–1997. 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.
| S.No. | Year | Shortage (%) |
| 1 | 1991 | 7.9 |
| 2 | 1992 | 7.8 |
| 3 | 1993 | 8.3 |
| 4 | 1994 | 7.4 |
| 5 | 1995 | 7.1 |
| 6 | 1996 | 9.2 |
| 7 | 1997 | 11.5 |
Answer 9:
