NCERT Class 8 Science Chapter 5 Solution
Brief Information: This post contains the solution for Chapter 5 Coal and Petroleum of Class 8 of the CBSE and also Gujarat Board (GSEB) books by GCERT (based on new NCERT).
Q1. What are the advantages of using CNG and LPG as fuels?
Ans. The Compressed Natural Gas (CNG) and Liquefied Petroleum Gas (LPG) has Advantages benefits as fuel
a.) They are cleaner form of fuel i.e. environment friendly. They emit less pollutant into atmosphere
b.) They are easy to handle and transport.
c.) They can be used directly for burning in homes and factories where it can be supplied through pipes.
Q.2 Name the petroleum product used for surfacing of roads.
Ans. Bitumen a petroleum product is used for surfacing of roads.
Q.3. Describe how coal is formed from dead vegetation. What is this process called?
Ans. Coal is formed from the remains of dead vegetation. The forest gets buried under the soil due to natural processes like flood. As more soil deposited over them, they were compressed. The temperature also rise as they sank deeper and deeper. Under high pressure and high temperature, dead plants got slowly converted to coal. It takes millions of years for dead plants to get converted into coal. These process is called Carbonisation.
Q.4. Fill in the blanks.
(a) Fossil fuels are Coal, Natural Gas and Petroleum.
(b) Process of separation of different constituents from petroleum is called refining.
(c) Least polluting fuel for vehicle is Compressed Natural Gas (CNG).
Q.5. Tick True/False against the following statements.
(a) Fossil fuels can be made in the laboratory. – F (False)
(b) CNG is more polluting fuel than petrol. – F (False)
(c) Coke is an almost pure form of carbon. – T (True)
(d) Coal tar is a mixture of various substances. – T (True)
(e) Kerosene is not a fossil fuel. – F (False)
Q.6. Explain why fossil fuels are exhaustible natural resources.
Ans. Fossil fuels are found in limited quantities in nature. The process of formation of fossil fuel take millions of year. On the other hand, human activities can lead to their exhaustion. Therefore, fossil fuels are exhaustible natural resource.
Q.7. Describe the characteristics and uses of coke.
Ans. Coke is almost pure form of carbon.
Characteristics: Tough, Porous and Black substance
Uses: In the manufacture of steel and in the extraction of metals.
Q.8. Explain the process of the formation of petroleum.
Ans. The formation of petroleum occurs in the sea bed. The marine organism die and get buried under the sand and clay. They are subjected to high heat and pressure. This transforms the dead organisms into petroleum and natural gas. The process of formation petroleum takes millions of years.
Q.9. Plot the Graph for following question.
1. 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.
Answer
2. The following table shows the total power shortage in India from 2004-2010. Show the data in the form of a graph. Piet shortage percentage for the years on the y-axis and the year on the x-axis.
Â
S. No. | Year | Shortage (%) |
1 | 2004 | 7.8 |
2 | 2005 | 8.6 |
3 | 2006 | 9.0 |
4 | 2007 | 9.5 |
5 | 2008 | 9.9 |
6 | 2009 | 11.2 |
7 | 2010 | 10.0 |
Answer
