NCERT Solutions for Class 8 Science Chapter 5 Coal and Petroleum

NCERT Solutions for Class 8 Science Chapter 5 Coal and Petroleum is written in a manner that makes it easy for anyone to understand the concepts better. It helps students do better and memorize more easily during times of intense pressure.

Students can easily review the answers they prepared and also know whether they learned it properly or not. Chapter 5 Class 8 Science NCERT Solutions will provide a lot of relevant content, making you well versed in variety of topics and able to easily recall your ideas.

Chapter 5 Coal and Petroleum Class 8 Science NCERT Solutions

Exercises

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

Solution

The advantages of using CNG and LPG are:
(i) CNG and LPG both produce fewer emissions than traditional fuels.
(ii) They are cheap as compared to other fuels.
(iii) They are easily available.
(iv) They can be supplied through pipelines.

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

Solution

Bitumen is a petroleum product used for surfacing the roads in place of coal tar.

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

Solution

Over millions of years as the remains of plants and other organisms are buried under layers of sediment and exposed to high temperatures and pressures. As these conditions increase, the organic matter is converted into carbon-rich material, forming coal. This process can take anywhere from thousands to millions of years depending on the environment in which it occurs. This process is called carbonisation.

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 vehicles is ______.

Solution

(a) Coal, petroleum, natural gas
(c) CNG (Compressed Natural Gas)
(b) Refining

5. Tick True/False against the following statements.
(a) Fossil fuels can be made in the laboratory.
(b) CNG is a more polluting fuel than petrol.
(c) Coke is almost a pure form of carbon.
(d) Coal tar is a mixture of various substances.
(e) Kerosene is not a fossil fuel.

Solution

(a) False
(b) False
(c) True
(d) True
(e) False

6. Explain, why fossil fuels are exhaustible natural resources?

Solution

A fossil fuel is derived from the remains of dead plants and animals. This process takes millions of years to occur. The known reserves of fossil fuels are limited, so these fuels are exhaustible.

7. Describe characteristics and uses of coke.

Solution

Coke is a tough, porous, black substance which is almost pure carbon and is used as a fuel and to reduce metal oxides to get metals. It is also used to manufacture steel and is used for home heating.

8. Explain the process of formation of petroleum.

Solution

Natural resources such as petroleum are exhaustible. Over the course of millions of years, petroleum is formed by organisms that lived in the sea. The bodies of these organisms settled on the bottom of the sea and became covered by layers of clay and sand. The dead organisms are converted into petroleum under high pressure and high temperature in the absence of air.

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

Solution