Class 8 science chapter 5 extra questions and Answers

In this page we have Class 8 science chapter 5 extra questions and Answers . This included Fill in the blanks, Match the column, Short answer type , True and false . Jumbled word questions, HOTS question and Long answer type question..Hope you like them and do not forget to like , social share and comment at the end of the page.

Very Short/Short Answer type questions

Question 1
Very short answer type questions:
(i)Name two types of natural resources.
(ii)Define the term “Carbonisation”.
(iii)Which type of coal is also known as black lignite?
(iv)In which process coal is heated up to 1000°C in the absence of air to form useful components?
(v)Which component is a mixture of hydrogen, methane, carbon monoxide and other gases?


(i)Exhaustible and inexhaustible natural resources.
(ii)Carbonisation is a process in which the dead vegetation is converted into coal after a long period of time.
(iv)Destructive Distillation
(v)Coal gas

Question 2
Short answer type of question:
(i)What are natural resources? Give examples.
(ii)How many types of natural resources and also define each of its category briefly?
(iii)Which is the most important exhaustible resource? Write its major types.
(iv)What do you understand by the term “Destructive Distillation”? Write at least two components prepared by this process.
(v)How do we extract petroleum gas? What is its use?


(i)The materials that are found in nature used by human beings to survive on this planet. Some of important examples are air, water, trees and coal.
(ii)Natural resources are mainly categorised into two types: some of the resources are limited on earth such type of natural resources are called exhaustible natural resources while the resources that sustain longer even after their continuous use, called inexhaustible natural resources.
(iii)The most important exhaustible resource is fossil fuels. There are three major parts of fossil fuels- coal, petroleum and natural gas.
(iv)The process of heating complex substances in a limited amount of air to produce simple components is called destructive distillation. Coal tar and coal gas are prepared by this method.
(v)We can extract petroleum gas by the process of fractional distillation. It is used for cooking (LPG cylinders).

Short answer type questions/HOTS

Question 3
Sam wants to establish iron and steel industry in his town. Therefore, he set-up a plant and identify that he requires an enormous amount of coke to produce the goods. What do you think Sam can do to get a large amount of coke and how does he produce coke?


I believe that Sam needs to set-up a destructive distillation plant in order to obtain a large number of coke. He can follow the process by heating the coal up to 1000°C but in the absence of air.

Question 4
How do you produce ammonium hydroxide solution? Name the process.


By dissolving ammonia in water, I can obtain ammonium hydroxide solution and this process is called ammonical liquor.

Question 5
How do you perform the process of fractional distillation? Name some useful fractions produced by this method.


The process of fractional distillation can be performed by following certain steps: -

  • Heating crude oil in a tall cylindrical column called fractionating column until it evaporates.
  • The condensed particles of crude oil move up and fitted in the horizontal trays attached to the fractionating column and form various fractions.
  • The fractional distillation separates the mixture of components due to the differences in their boiling points.
  • The components adjust according to their boiling point rate. For example, the lowest boiling point component at the top and highest at the bottom.

Question 6
Complete the following table by providing correct process of producing the substance.
Class 8 science chapter 5 extra questions and Answers


  1. Destructive Distillation
  2. Fractional Distillation
  3. Ammonical Liquor
  4. Carbonisation
  5. Fractional Distillation

Question 7
What is Peat? Write it uses and appearance.


Peat is a type of coal that is dark brown in colour. The formation of peat takes place due to the dead plants buried for a longer period of time. It is the least carbon containing coal that is used for creating industrial fuel.

Question 8
Distinguish between lignite and bituminous.


The differences between lignite and bituminous are given below: -

Question 9
Do you illustrate the difference between Petrol and Petroleum? Support your answer.


No, Petrol and Petroleum are two different terms. Petroleum or crude oil is a natural resource formed by the dead and decaying matter found under the bottom of sea while petrol is a fraction of petroleum produced by the process called fractional distillation.

Question 10
What do we call the process of converting dead vegetation into coal? Also write the types of coal and the carbon content present in them.


The process of converting dead vegetation into coal is called carbonisation. There are four major types of coal: -

  • Peat: It has least carbon content.
  • Lignite: It has 60% carbon content.
  • Bituminous: It has 70%-86% carbon content.
  • Anthracite: It has 86% carbon content.

Long answer type questions:

Question 11
Describe the process of destructive distillation. Also draw a well-labelled diagram of it.


Destructive distillation is the process of producing simpler substances by heating a complex substance in the presence of limited amount of air. This process is used to obtain useful components like coke, coal tar, coal gas and ammonical liquor by heating coal up to 1000°C in the absence of air.
Class 8 science chapter 5 extra questions and Answers

Question 12
Describe the components of petroleum and their uses in details.


The fractions of petroleum are collected in the horizontal trays attached to the fractionating column. This process of accumulating the fractions of petroleum is called fractional distillation. Some important fractions and their uses are given below: -

  • Petroleum gas: This fraction is used in industries, home and store in the cylinders called Liquid Petroleum Gas (LPG).
  • Petrol (Gasoline): This is one of the important fractions which is used as a fuel for vehicles and aircrafts as well as solvent for dry cleaning.
  • Naphtha: It is used to produce different kinds of chemicals.
  • Kerosene: One of the most common fraction that is used to lighting stoves and lanterns.
  • Diesel: It is used as a fuel for vehicles and generators.
  • Fuel Oil: This fraction of petroleum is used in ships, power stations, factories and for manufacturing petroleum jelly.
  • Residue (Bitumen): It is used for surfacing of roads and in paints.


This Class 8 science chapter 5 extra questions and Answers is prepared keeping in mind the latest syllabus of CBSE . This has been designed in a way to improve the academic performance of the students. If you find mistakes , please do provide the feedback on the mail.

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