1. What are the advantages of using CNG and LPG as fuels?
Ans:
The advantages of using CNG (Compressed Natural Gas) and LPG (Liquefied Petroleum Gas) as fuels are:
They burn easily and efficiently.
They produce a high amount of heat energy upon combustion.
They can be conveniently transported through pipelines.
They are clean fuels, as they do not release smoke or harmful pollutants when burned, reducing air pollution.
2. Name the petroleum product used for surfacing of roads.
Ans:
The petroleum product used for surfacing roads is bitumen.
3. Describe how coal is formed from dead vegetation. What is this process called?
Soln:
Millions of years ago, dense forests became buried under layers of soil due to natural processes. Over time, more soil accumulated on top, and the buried vegetation was subjected to increasing pressure and temperature. This extreme heat and pressure caused the plant material to undergo chemical changes, gradually transforming it 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) The process of separation of different constituents from petroleum is called _____________ .
(c) The least polluting fuel for a vehicle is ______________ .
Soln:
(a) Coal, Petroleum, and natural gas.
(b) refining.
(c) 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 a more polluting fuel than petrol. (T/F)
(c) Coke is the most 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)
Soln:
a) False
b) False
c) True
d) True
e) False
6. Explain why fossil fuels are exhaustible natural resources.
Soln:
Fossil fuels are exhaustible because their formation takes millions of years. The process involves the burial of dead vegetation and animals under layers of soil, where they undergo chemical changes due to high temperature and pressure. This process cannot be replicated in laboratories, and the reserves of fossil fuels are finite. If fossil fuels are used at a rapid rate, they will be exhausted as their formation takes much longer than their consumption.
7. Describe the characteristics and uses of coke.
Soln:
Characteristics:
i) Coke is tough.
ii) Coke is porous.
iii) Coke is black in color.
Uses:
i) It is used in the manufacture of steel.
ii) It is used in the extraction of metals as a reducing agent.
8. Explain the process of the formation of petroleum.
Soln:
Petroleum is formed from the remains of dead marine organisms that were buried under layers of sand and clay millions of years ago. Due to the lack of oxygen, high temperature, and immense pressure, these organic materials slowly transformed into petroleum and natural gas.
9. The following table shows the total power shortage in India from 1993–1999. 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.
