Coal and Petroleum
Class 8 Science - CBSE Guess and Guide | NCERT Questions Bank
NCERT answers for CBSE Sample Questions - Class 8 Science Chapter 5 Coal and Petroleum
Question.1: What is pure form of carbon?
Answer: Coke.
Question.2: What are natural resources? How
many types of natural resources are available in nature?
Answer: Resources which are obtained
from nature are called Natural Resources.
On the basis of availability of these resources (materials) can be divided into
two types:
1. Inexhaustible Natural Resources
- natural resources which cannot be finished by human activities like -
sunlight, air
2. Exhaustible Natural Resources - are those
resources which are present in limited quantity and may be finished by human
activities like - wildlife, coal, petroleum.
Question.3: What are inexhaustible natural
resources? Give two examples of inexhaustible natural resources.
Answer: See answer of above question.
Question.4: What is coal tar?
Answer: Coal Tar is a black liquid that is produced
during destructive distillation of coal. Coal Tar has an unpleasant smell. Earlier
coal tar was used for metalling the roads which. Now coal tar is mainly used to
produce many types of industrial products, consumables.
Question.5: What are exhaustible natural
resources? Give two examples of exhaustible natural resources.
Answer: See answer of above question no. 2.
Question.6: What is Petroleum? Write a
short note on Petroleum.
Answer: Petroleum is an exhaustible, natural fossil fuel
which is extracted from beneath the surface of the earth. Petroleum was formed
from the dead bodies of sea organisms which got buried under the sea bed. Over
millions of years, in absence of air, under high temperature and pressure these
bodies got transformed into petroleum and natural gas.
Petroleum is a dark, oily liquid with some unpleasant
odour. It has various useful constituents like - petroleum gas (LPG), petrol,
kerosene, diesel, lubricating oil, paraffin wax, bitumen, etc. which are separated
from it by the process known as Fractional
Distillation.
Due to its high commercial importance petroleum is known
as “Black Gold”.
Question.7: What are fossil fuels?
Answer: Those fuels which got formed by the decomposition
of the dead remains of living organisms for a long period of time are called Fossil
Fuels. Examples of fossil fuels - coal and petroleum.
Question.9: Define and differentiate
between Coal and Coal Gas. [Write short notes on Coal and Coal Gas.]
Answer: Coal
is a natural, exhaustible fossil fuel which is found under the surface of the
earth. Coal has formed from the dead vegetation over hundreds of millions years
through Carbonisation. It is a black,
hard solid material. When heated in air it burns and produces mainly carbon
dioxide. Coal is mainly used as a fuel in various industries. Several other
products like - coke, coal-tar, coal gas etc. obtained after processing coal,
are further used for various purposes. In thermal power plants coal is used to
produce electricity. In India coal is found mainly in Bihar, Jharkhand, West
Bengal and MP.
Coal Gas is
a fuel which is obtained during the processing of coal to get coke. Many years
ago coal gas was used in America and Britain for street-lighting.
Question.10: What is Petroleum Refining?
Answer: The extraction process in which different
constituents of petroleum are separated, known as Fractional Distillation, is
also known as Petroleum Refining.
Question.11: Name three products obtained
from Petroleum Refining along with their uses.
Answer: Three products obtained from Petroleum Refining
and their uses -
L.P.G: Liquefied Petroleum Gas, used as
domestic fuel.
Kerosene: Used as fuel for
burning in stoves, lamps, automobiles.
Petrol: As fuel for light
vehicles, aviations, dry cleaning of fabrics.
Question.12: What is carbonization?
Answer: The slow process of conversion of dead vegetation
into coal is called Carbonisation.
Question.13: Which gas is mainly released
when coal is burnt?
Answer: Carbon dioxide.
Question.14: To which process coal is put
to get some useful products?
Answer: Destructive distillation.
Question.15: What is destructive distillation?
Answer: Burning coal in absence of oxygen to get coke and
other useful products is called Destructive
Distillation.
Question.16: Why cannot we prepare
petroleum in our laboratories?
Answer: Petroleum was formed in
hundreds of millions of years by conversion of dead organisms (plants and animals)
buried under the surface of the earth under high temperature and pressure
conditions.
Such conditions necessary for
conversion of dead bodies into fossil fuel cannot be artificially created in
laboratories and therefore, we cannot we prepare petroleum in our laboratories.
More
study from Chapter 5, Class 8 NCERT Science
No comments:
Write comments