Coal And Petroleum
Class 8th Science CBSE Solution
- What are the advantages of using CNG and LPG as fuels?
- Name the petroleum product used for surfacing of roads.
- Describe how coal is formed from dead vegetation. What is this process called?…
- Fill in the banks. (a) Fossil fuels are _______, _________and__________. (b) Process of…
- Tick True/False against the following statements. (a) Fossil fuels can be made in the…
- Explain why fossil fuels are exhaustible natural resources.
- Describe characteristics and uses of coke.
- Explain the process of formation of petroleum.
- The following Table shows the total power shortage in India from 1991 - 1997. Show the…
Exercises
Question 1.What are the advantages of using CNG and LPG as fuels?
Answer:
The advantages of using CNG(Compressed Natural Gas) and LPG(Liquefied Petroleum Gas) as fuels are listed below:
(a) They are more efficient than fossil fuels.
(b) They can be easily transported either through cylinders or through pipelines.
(c) They are less polluting than other fossil fuels.
(d) They are clean fuels and do not give smoke when burnt.
(e) They give a lot of heat energy when burnt.
Question 2.
Name the petroleum product used for surfacing of roads.
Answer:
Bitumen, a petroleum product, is used for surfacing roads instead of coal-tar.
Question 3.
Describe how coal is formed from dead vegetation. What is this process called?
Answer:
When the dead remains of plants, due to natural processes like storms, floods, and earthquakes, got buried under the earth millions of years ago. These got compressed as more and more soil got deposited over them. Due to intense heat and pressure inside the earth, slowly with time, they turned into coal. The process of conversion of dead remains of plants into coal is called carbonization.
Question 4.
Fill in the banks.
(a) Fossil fuels are _______, _________and__________.
(b) Process of separation of different constituents from petroleum is called __________.
(c) Least polluting fuel for vehicles 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 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:
(a) False
(b) False
(c) True
(d) True
(e) False
Question 6.
Explain why fossil fuels are exhaustible natural resources.
Answer:
Fossil fuels are present on the earth surface in a limited quantity and the new mineral growth formed from dead remains of animals and plant require millions and millions of years to form under high temperature and pressure conditions . Such extreme conditions cannot be produced in the laboratory. Thus, due to the limited quantity and time to renew it, we keep fossil fuel into the category of exhaustible natural resources.
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.
The uses of coke are:
1) Coke burns much cleaner than coal.
2) It provides more energy for the same mass as coal.
3) It is used in manufacture of steel and in extraction of many minerals.
Question 8.
Explain the process of formation of petroleum.
Answer:
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.
Answer:
We show the data in from of a bar graph.
