NCERT Solutions for Class 8 Science Chapter 6 – Combustion and Flame
Orchid International School recognizes the significant role of NCERT Solutions for Class 8 Science Chapter 6, "Combustion and Flame," in the academic journey of science students. The information and explanations provided on ignition and fire arrangements are instrumental in helping students grasp these topics in an engaging and comprehensive manner.
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The NCERT Solutions for Class 8 Science Chapter 6 – Combustion and Flame are tailored to help the students master the concepts that are key to success in their classrooms. The solutions given in the PDF are developed by experts and correlate with the CBSE syllabus of 2023-2024. These solutions provide thorough explanations with a step-by-step approach to solving problems. Students can easily get a hold of the subject and learn the basics with a deeper understanding. Additionally, they can practice better, be confident, and perform well in their examinations with the support of this PDF.
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Access Answers to NCERT Solutions for Class 8 Science Chapter 6 – Combustion and Flame
Students can access the NCERT Solutions for Class 8 Science Chapter 6 – Combustion and Flame. Curated by experts according to the CBSE syllabus for 2023–2024, these step-by-step solutions make Science much easier to understand and learn for the students. These solutions can be used in practice by students to attain skills in solving problems, reinforce important learning objectives, and be well-prepared for tests.
Combustion and Flame
Explain How the Use of CNG in Automobiles Has Reduced Pollution in Our Cities.
The use of CNG in automobiles has reduced pollution in our cities because it is a clean fuel and the amount of unburnt fuel in CNG is very less compared to petroleum. It does not produce smoke and harmful substances that are produced in petroleum.
Fill in the Blanks:
a) Burning of wood and coal causes ______ of air.
b) A liquid fuel used in homes is _____.
c) Fuel must be heated to its ____ before it starts burning.
d) The fire produced by oil cannot be controlled by _____.
a) Burning of wood and coal causes pollution of air.
b) A liquid fuel used in homes is Liquified Petroleum Gas (LPG).
c) Fuel must be heated to its ignition temperature before it starts burning.
d) Fire produced by oil cannot be controlled by water.
List Conditions Under Which Combustion Can Take Place.
Combustion takes place under the following three conditions:
(i) In the presence of fuel.
(ii) In the presence of oxygen (air).
(iii) In the presence of heat - the minimum temperature at which a substance catches fire, known as ignition temperature.
Compare LPG and Wood as Fuels.
The difference between LPG and wood as fuels is:
|
LPG |
Wood |
|
LPG is a by-product of natural gas and crude oil refining. |
Wood is a fuel that is obtained from trees. |
|
Its efficiency is 55,000 kJ/kg 55,000 ��/��. |
Its efficiency is 17,000−22,000 kJ/kg 17,000−22,000 ��/��. |
|
It is a gaseous fuel. |
It is a solid fuel. |
|
It produces less pollution on combustion. |
It produces a lot of smoke on combustion and causes respiratory problems. |
Give Reasons.
a) Water is not used to control fires involving electrical equipment.
b) LPG is a better domestic fuel than wood.
c) Paper by itself catches fire easily whereas a piece of paper wrapped around an aluminum pipe does not.
a) Water is not used to control fires involving electrical equipment because water is a good conductor of electricity due to which the person may be electro-conducted and it may damage the equipment.
b) LPG is a better domestic fuel than wood because wood produces a lot of smoke on combustion and causes respiratory problems. Also, its efficiency is lower than LPG.
c) Paper by itself catches fire easily whereas a piece of paper wrapped around an aluminum pipe does not because aluminum is a good conductor of heat which absorbs the heat from the paper and the paper does not catch fire. Whereas, the paper by itself catches fire.
Make a Labeled Diagram of a Candle Flame.
A labeled diagram of a candle flame is:
Name the Unit in Which the Calorific Value of a Fuel is Expressed.
“Kilo Joule per Kilogram
(kJ/kg)
(��/��)” is used to express the calorific value of a fuel.
Explain how
C
O
2
��2
is able to control fires.
We know that combustion takes place under the following three conditions:
(i) In the presence of oxygen (air).
(ii) In the presence of fuel.
(iii) In the presence of heat - the minimum temperature at which a substance catches fire, known as ignition temperature.
We can control the fire if any one of the three conditions is not met.
(i)
C
O
2
��2 is heavier than oxygen and hence it acts as a protective blanket and prevents oxygen from reaching the fire.
(ii) Since
C
O
2
��2 is stored in a liquid state, therefore, when it is used on the fire, it expands and cools which lowers down the temperature. This prevents heat from reaching the fire.
It is Difficult To Burn a Heap of Green Leaves, but Dry Leaves Catch Fire Easily. Explain.
It is difficult to burn a heap of green leaves, but dry leaves catch fire easily because combustion takes place in the presence of heat - the minimum temperature at which a substance catches fire, known as ignition temperature. Green leaves have high moisture than dry leaves and hence, it takes more time for green leaves to reach ignition temperature than dry leaves.
Which Zone of a Flame Does a Goldsmith Use for Melting Gold and Silver and Why?
Goldsmiths use the outermost zone of the flame to melt gold and silver because gold and silver have a high melting point and the outermost part undergoes complete combustion and it is the hottest part of the flame which supply the adequate amount of heat required for melting.
In an Experiment
4.5 kg
4.5 ��
of a fuel was completely burnt. The heat produced was measured to be
180,000 kJ
180,000 ��
. Calculate the calorific value of the fuel.
The amount of heat released during combustion of
1 kg
1 �� fuel is known as calorific value i.e.,
Calorific Value=
Heat produced during combustion
Quantity of fuel
��������� �����=���� produced during combustion�������� of fuel
⇒Calorific Value=
180,000
4.5
kJ/kg
⇒��������� �����=180,0004.5 ��/��
∴Calorific Value=40,000 kJ/kg
∴��������� �����=40,000 ��/��
Can the Process of Rusting Be Called Combustion? Discuss.
A chemical process in which a substance reacts with oxygen to give off heat is called combustion. When an iron metal combines with the oxygen in the presence of water to form a compound iron oxide is known as rusting.
Therefore, the process of rusting can be called combustion because in both processes, heat, and light are produced. Rusting is known as slow combustion.
Abida and Ramesh Were Doing an Experiment in Which Water Was To Be Heated in a Beaker. Abida Kept the Beaker Near the Wick in the Yellow Part of the Candle Flame. Ramesh Kept the Beaker in the Outermost Part of the Flame. Whose Water Will Get Heated in a Shorter Time?
A labeled diagram of a candle flame is:
Observe that the innermost zone of the candle which is near to the wick is the least hot whereas the outer zone of the candle is the hottest part of the candle flame.
Since Ramesh kept the beaker in the outermost part of the flame, therefore his beaker will be heated in a shorter time as compared to Abida.
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Frequently Asked Questions
The NCERT solution for Class 8 Chapter 6 : Combustion and Flame is important as it provides a structured approach to learning, ensuring that students develop a strong understanding of foundational concepts early in their academic journey. By mastering these basics, students can build confidence and readiness for tackling more difficult concepts in their further education.
Yes, the NCERT solution for Class 8 Chapter 6 : Combustion and Flame is quite useful for students in preparing for their exams. The solutions are simple, clear, and concise allowing students to understand them better. They can solve the practice questions and exercises that allow them to get exam-ready in no time.
You can get all the NCERT solutions for Class 8 Science Chapter 6 from the official website of the Orchids International School. These solutions are tailored by subject matter experts and are very easy to understand.
Yes, students must practice all the questions provided in the NCERT solution for Class 8 Science Chapter 6 : Combustion and Flame as it will help them gain a comprehensive understanding of the concept, identify their weak areas, and strengthen their preparation.
Students can utilize the NCERT solution for Class 8 Science Chapter 6 effectively by practicing the solutions regularly. Solve the exercises and practice questions given in the solution.