Last Updated on February 20, 2025 by XAM CONTENT
Hello students, we are providing case study questions for class 8 science. Case study questions are the new question format that is introduced in CBSE board. The resources for case study questions are very less. So, to help students we have created chapterwise case study questions for class 8 science. In this article, you will find case study questions for cbse class 8 science Chapter 4 Combustion and Flame.
| Chapter | Combustion and Flame |
| Type of Questions | Case Study Questions |
| Nature of Questions | Competency Based Questions |
| Board | CBSE |
| Class | 8 |
| Subject | Science |
| Useful for | Class 8 Studying Students |
| Answers provided | Yes |
| Difficulty level | Mentioned |
| Important Link | Class 8 Science Chapterwise Case Study |
Case Study Questions on Combustion and Flame
Questions
(I) The air that we breathe today is more polluted than it was before. More factories more vehicles greater use of aerosols and sprays, increasing number of refrigerators and air conditioners that release CFC gases, have all contributed toward pollution. When certain chemicals from the smoke and fumes rise up into the air they mix with the water vapour in the clouds and make it acidic. When rain or snow falls from such polluted clouds, it is also acidic in nature. This acidic rain falls on the leaves of trees, on the fertile soil and also runs into lakes and rivers. The effects of the rain are disastrous. Trees slowly lose their leaves and die. Fertile soil turns acidic and damages the plants and crops. The fish and animals living in lakes or seas are killed. Even our drinking water can be affected. Many forests all over the world have suffered severe damage on account of acid rains. Before it is too late, we must try and put a stop to the millions of vehicles and chimneys pouring harmful fumes into the air.
Q.1. Which gas is released by the incomplete combustion of fuels?
(a) Oxygen
(b) Hydrogen
(c) Carbon monoxide
(d) None of the above.
Difficulty Level: Easy
Ans. Option (c) is correct.
Explanation: Carbon monoxide is a poisonous gas, which is produced by the incomplete combustion of fuels.
Q. 2. Emissions of sulphur dioxide and nitrogen oxide causes:
(a) Pollution
(b) Acid rain
(c) Deforestation
(d) None of the above.
Difficulty Level: Easy
Ans. Option (b) is correct.
Explanation: Acid rains are caused by emissions of sulphur dioxide and nitrogen oxide, which react with the water molecules in the atmosphere to produce acid. It has a very harmful effect on plants, land and aquatic animals and infrastructure.
Q.3. What is fire triangle?
Difficulty Level: Medium
Ans. For the generation of fire, we need three things to be present simultaneously:-
- Some sort of fuel or combustible material.
- A heat source to raise the temperature of the fuel to its ignition temperature.
- Enough oxygen to sustain combustion. So, if we remove any one of these resources, the fire can be controlled.
Q.4. How carbon dioxide is responsible for global warming?
Difficulty Level: Medium
Ans. Molecules of carbon dioxide gas have a tendency to absorb the heat. The carbon dioxide molecules present in the atmosphere absorb this heat energy and does not allow it to escape into space. So, more the amount of carbon dioxide molecules in the atmosphere more will be the temperature and eventually causes global warming.
Also check
- Light Class 8 Case Study Questions Science Chapter 13
- Some Natural Phenomena Class 8 Case Study Questions Science Chapter 12
- Chemical Effects of Electric Current Class 8 Case Study Questions Science Chapter 11
- Sound Class 8 Case Study Questions Science Chapter 10
- Friction Class 8 Case Study Questions Science Chapter 9
- Force and Pressure Class 8 Case Study Questions Science Chapter 8
- Reaching the Age of Adolescence Class 8 Case Study Questions Science Chapter 7
- Reproduction in Animals Class 8 Case Study Questions Science Chapter 6
- Conservation of Plants and Animals Class 8 Case Study Questions Science Chapter 5
- Combustion and Flame Class 8 Case Study Questions Science Chapter 4
- Coal and Petroleum Class 8 Case Study Questions Science Chapter 3
- Microorganisms: Friend and Foe Class 8 Case Study Questions Science Chapter 2
- Crop Production and Management Class 8 Case Study Questions Science Chapter 1
Topics from which case study questions may be asked
- Learning what is meant by combustion?
- Knowing types of combustion.
- Discuss various methods used to control fire.
- Learning the structure of flame.
- To know more about fuel and fuel efficiency.
We use various kinds of fuel such as petrol, diesel, CNG, LPG, coal, wood etc., in our daily life. Some of these fuels burn with a flame while some do not. This chapter deals with the chemical processes involved in burning and the type of flames produced in the processes. So based on this, the above topic list is provided.
