In this post we will see class 8th chapter 5th solution.
You can check the Complete Science Solution here – NCERT Class 8th Science Solutions – Complete Solution List
Chapter 5 Solutions
1. What are the advantages of using compressed natural gas (CNG) and liquified gas (LPG) are as fuels ?
Answer – The advantages of using compressed natural gas (CNG) and liquified petroleum gas (LPG) are as fuels .
(i) They can be burnt easily.
(ii) They can be transported easily through pipe lines.
(iii) They are clean fuels and do not give smoke when burnt.
(iv) They give a lot of heat energy when burnt.
2. Name the petroleum product used for surfacing of roads.
Answer – Bitumen, a petroleum product, is used for surfacing roads.
3. Describe how coal is formed from dead vegetation. What is this process called?
Answer – Millions of year ago, dense forest got buried under the soil due to natural process like storms, floods, and earthquakes. These got compressed as more and more soil got deposited over them. When they got converted into coal. This process of formation of coal from dead vegetation is called carbonization.
4. Fill in the blanks.
(a) Fossil fuels are ________, ________ and _________.
(b) Process of separation of different constituents from petroleum is called _________.
(c) Least pollution fuel for vehicle is __________.
Answer – (a) Fossil fuels are __coal__, __petroleum __ and __natural gas __.
(b) Process of separation of different constituents from petroleum is called __refining__.
(c) Least polluting fuel for vehicles is __Compressed natural gas (CNG)__.
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 – (a) Fossil fuels can be made in the laboratory. (F)
(b) CNG is more polluting fuels than petrol. (F)
(c)Coke is almost pure form of carbon (T)
(d) Coal tar is a mixture of various substances. (T)
(e) Kerosene is not a fossil fuel. (F)
6. Explain why fossil fuels are exhaustible natural resources.
Answer – Fossil fuels require million of years to form from the dead vegetation and animal that get buried deep inside the earth. They require high temperature and pressure for their formation which cannot be provided in the laboratory. Thus, fossils are limited. Therefore, the use of fossil fuels at this rate will lead to their exhaustion.
7. Describe characteristics and uses of coke.
Answer – Characteristics of coke are –
(i) Tough
(ii) Porous
(iii) Black in colour
Uses of coke:
(i) In manufacture of steel.
(ii)In the extraction of metals (as a reducing agent).
8. Explain the process of formation of petroleum.
Answer – Petroleum was formed from dead organisms that got buried in the sea millions or year 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.
9. The following table show 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 2 3 4 5 6 7 |
1991 1992 1993 1994 1995 1996 1997 |
7.9 7.8 8.3 7.4 7.1 9.2 11.5 |
Answer –
You can check the Complete Science Solution here – NCERT Class 8th Science Solutions – Complete Solution List
You can see the other posts here
- Solution Class 8th Science Chapter 5 – Coal and Petroleum
- Class 8th NCERT Science Solution Chapter 6 – Combustion and Flame
- Class 8th NCERT Science Solution Chapter 7 – Conversation of Plant and Animal
- Class 8th NCERT Science Solution Chapter 9 – Reproduction in Animals
Tags – NCERT class 8th chapter 5 solution, Solution for class 8th chapter 5, NCERT solution class 8th, Class 8th chapter 5 solution, Chapter 5 class 8th science, NCERT class 8th solution, Class 8th solution.
