Exercise
1) What are the advantages of using CNG and LPG as
fuels?
fuels?
ANSWER:-The advantages are’-:-
(i) They can be burnt directly.
(ii) They can be transported easily
through pipe lines.
through pipe lines.
(iii) They are clean fuels and do not
give smoke when burnt.
give smoke when burnt.
(iv) They give a lot of heat energy
when burnt.
when burnt.
2) Name the petroleum product used for surfacing of
roads.
roads.
ANSWER:-Bitumen, a petroleum product, is
used for surfacing roads.
used for surfacing roads.
3) Describe how coal is formed from dead vegetation. What
is this process
is this process
called?
ANSWER:-A long time back, about 300 million
years ago the earth had dense forests in low lying wetland areas. Due to
natural processes, like earth quakes, flooding, these forests got buried under the soil,
rocks and other land masses. With the passage of time, 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.
years ago the earth had dense forests in low lying wetland areas. Due to
natural processes, like earth quakes, flooding, these forests got buried under the soil,
rocks and other land masses. With the passage of time, 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.
4) Fill in the blanks:
(a) Fossil fuels are –Coal–, –Petroleum– and –Natural
gas–.
gas–.
(b) Process of separation of different constituents from
petroleum is called –Refining–.
petroleum is called –Refining–.
(c) Least polluting fuel for vehicle is –CNG–
5) Tick True/False against the following statements:
(a) Fossil fuels can be made in the
laboratory. ( F)
laboratory. ( F)
(b) CNG is more polluting fuel than
petrol. ( F)
petrol. ( F)
(c) Coke is almost pure form of
carbon. ( T )
carbon. ( T )
(d) Coal tar is a mixture of various
substances. ( T )
substances. ( T )
(e) Kerosene is not a fossil fuel.
(F)
(F)
6) Explain why fossil fuels are exhaustible natural
resources.
resources.
ANSWER:-Fossil fuels are exhaustible
natural resources, as limited fossil fuels reserves like coal, petroleum, natural
gas are being depleted very fast by human activities like rapid urbanization,
industrialization and transportation.
natural resources, as limited fossil fuels reserves like coal, petroleum, natural
gas are being depleted very fast by human activities like rapid urbanization,
industrialization and transportation.
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).
Coke is used in the homes for cooking, heating and in
industries, for manufacturing of steel and extraction of many metals. Earlier
it was also used in steam engines for rail transportation. It is also used in
thermal power plants to produce electricity.
industries, for manufacturing of steel and extraction of many metals. Earlier
it was also used in steam engines for rail transportation. It is also used in
thermal power plants to produce electricity.
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.
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.
9) The following Table shows the
total power shortage in India from 1991–1997. Shown 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. (REFER TO THE BOOK)
total power shortage in India from 1991–1997. Shown 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. (REFER TO THE BOOK)
ANSWER:-
