Exercises
Question 1
What are the advantages of using CNG and LPG as fuels?
Answer
Following are the advantages of using CNG and LPG as fuels:
- They are cleaner fuel as they do not cause much pollution.
- They can be easily transported through pipelines to long distances.
- They can be used directly for burning in homes and factories where it can be supplied through pipes.
Question 2
Name the petroleum product used for surfacing of roads.
Answer
Bitumen is a petroleum product that is used in place of coal-tar for metalling or surfacing the roads.
Question 3
Describe how coal is formed from dead vegetation. What is this process called?
Answer
About 300 million years ago the earth had dense forests in low lying wetland areas. Due to natural processes, like flooding, these forests got buried under the soil. As more soil deposited over them, they were compressed. The temperature also rose as they sank deeper and deeper. Under high pressure and high temperature, dead plants got slowly converted to coal.
As coal contains mainly carbon, the slow process of conversion of dead vegetation into coal is called carbonisation. Since it was formed from the remains of vegetation, coal is also called a fossil fuel
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
(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 vehicle is CNG.
Question 5
Tick True/False against the following statements.
(a) Fossil fuels can be made in the laboratory.
(b) CNG is more polluting fuel than petrol.
(c) Coke is almost pure form of carbon.
(d) Coal tar is a mixture of various substances.
(e) Kerosene is not a fossil fuel.
Answer
(a) False
Corrected Statement — Fossil fuels cannot be made in the laboratory.
(b) False
Corrected Statement — CNG is less polluting fuel than petrol.
(c) True
(d) True
(e) False
Corrected Statement — Kerosene is a fossil fuel.
Question 6
Explain why fossil fuels are exhaustible natural resources.
Answer
Fossil fuels are exhaustible natural resources due to their finite availability. These resources have a limited supply that will only last for a few hundred years, and their formation is an extremely slow process, taking millions of years as organic matter undergoes transformation into fuel. So, once these fossil fuel reserves are over, they cannot be readily replenished, contributing to their status as exhaustible natural resources.
Question 7
Describe characteristics and uses of coke.
Answer
Coke is a tough, porous and black substance. It is an almost pure form of carbon.
Coke is used in the manufacture of steel and in the extraction of many metals. It is also used as a fuel.
Question 8
Explain the process of formation of petroleum.
Answer
Petroleum was formed from plants and animals living in the sea. As these organisms died, their bodies settled at the bottom of the sea and got covered with layers of sand and clay. Over millions of years, absence of air, high temperature and high pressure transformed the 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
Power shortage graph is shown below:
