Industry-relevant training in Business, Technology, and Design to help professionals and graduates upskill for real-world careers.
Fun, engaging games to boost memory, math fluency, typing speed, and English skills—perfect for learners of all ages.
Enroll to start learning
You’ve not yet enrolled in this course. Please enroll for free to listen to audio lessons, classroom podcasts and take practice test.
Listen to a student-teacher conversation explaining the topic in a relatable way.
Signup and Enroll to the course for listening the Audio Lesson
Today, we'll discuss combustion! Can anyone tell me what combustion is?
Isn't it when something burns, like wood or coal?
Exactly! Combustion is when a substance reacts with oxygen to produce heat and light. This reaction is essential for various energy-consuming activities.
Are there different types of combustion?
Great question! Yes, we have spontaneous combustion, explosion, and rapid combustion. How about we remember this with the acronym RSE, for Rapid, Spontaneous, and Explosion?
That sounds helpful!
At the end of our session, remember combustion equals fire and heat!
Signup and Enroll to the course for listening the Audio Lesson
Now let's talk about fuels. What fuels do you use at home?
We use LPG, kerosene, and sometimes wood.
Correct! Fuels can be solid, liquid, or gas. Knowing their properties helps us understand their combustion better.
What about the environmental impact of these fuels?
Excellent point! Fuels emit harmful by-products when burned. It's vital we learn about cleaner alternatives.
I read that CNG is a cleaner fuel.
Exactly! CNG minimizes harmful emissions.
So, we should aim to use fuels that are efficient and environmentally friendly!
Signup and Enroll to the course for listening the Audio Lesson
Let's discuss what conditions are necessary for combustion!
I think we need fuel and oxygen.
Good! We also require heat to reach the ignition temperature. Our acronym for this is F.O.H: Fuel, Oxygen, Heat.
What happens if any one of them is missing?
Without any of these components, combustion cannot occur! It's key knowledge for controlling fires too.
Signup and Enroll to the course for listening the Audio Lesson
Finally, let's discuss how fuels impact our environment.
I heard burning fuels causes pollution?
That’s right! Burned fuels can release carbon dioxide and carbon monoxide, affecting our air quality severely.
What about global warming?
Burning fossil fuels significantly contributes to global warming. We should look into sustainable fuel sources.
So, protecting our environment is linked to how we use our fuels!
Exactly! Remember, our choices in fuel can protect our planet.
Read a summary of the section's main ideas. Choose from Basic, Medium, or Detailed.
The section delves into combustion as the process where substances react with oxygen to release heat and light. It discusses the requirements for combustion, including fuel, heat, and oxygen, and introduces the different types of combustion, such as rapid and spontaneous. It also emphasizes the environmental impact of using various fuels.
Combustion is defined as a chemical process in which a substance reacts with oxygen, resulting in the release of heat and light. Substances that undergo combustion are known as combustible or fuel. Fuels can be solid, liquid, or gas, and their primary requirement for combustion includes a sufficient supply of oxygen, appropriate heat, and an ignition temperature that the fuel must reach before it ignites.
This section also differentiates between various fuels used in homes and industries, highlighting combustible materials like wood, kerosene, and coal, compared to non-combustible items like iron and stone. It demonstrates through activities how different materials respond when subjected to heat, outlining their combustion characteristics, fire control measures, and the necessity of air for burning.
The section explains various combustion types:
1. Rapid Combustion - Occurring at a fast pace, producing heat and light, illustrated by gas stoves.
2. Spontaneous Combustion - A type that ignites without an external flame, like certain coal dust cases.
3. Explosion - Here enormous heat, light, sound, and gas are released suddenly, often observed with fireworks.
The implications of burning fuels lead to harmful by-products that affect air quality, namely carbon monoxide, causing pollution and health risks. Additionally, burning processes contribute to global issues like global warming and acid rain, culminating in essential discussions on replacing harmful fuels with cleaner alternatives like CNG.
Overall, this section emphasizes combustion's fundamental role in energy production while highlighting the urgent need to address its environmental impact.
Dive deep into the subject with an immersive audiobook experience.
Signup and Enroll to the course for listening the Audio Book
The substances which burn in air are called combustibles.
Combustion refers to a chemical process where a substance reacts with oxygen, resulting in the release of heat and light. If a material can burn in air, it is defined as 'combustible'. This means that not all materials can catch fire; only those that can react with oxygen are classified in this way.
Think of burning a piece of wood in a campfire. The wood is clearly a combustible material. However, a stone won't catch fire no matter how hot it gets. Thus, it is not combustible.
Signup and Enroll to the course for listening the Audio Book
Oxygen (in air) is essential for combustion.
For combustion to occur, oxygen is necessary. This means that a fire can only start and continue burning if oxygen is available in the environment. Without oxygen, combustion cannot take place, which is why putting a lid on a burning candle will extinguish the flame.
Imagine trying to light a fire under water—it simply won’t work. Similarly, if you wrap a fire in a blanket to block the air, the fire will go out due to the lack of oxygen.
Signup and Enroll to the course for listening the Audio Book
During the process of combustion, heat and light are given out.
When substances burn, they undergo chemical changes resulting in the release of energy in the form of heat and light. This is why flames give off light and why we feel warmth when we are near a fire.
Think of lighting a birthday candle. Once lit, it not only helps you celebrate but also emits light and warmth to those nearby. This is a direct consequence of combustion.
Signup and Enroll to the course for listening the Audio Book
Ignition temperature is the lowest temperature at which a combustible substance catches fire.
Every combustible material has a specific temperature at which it will ignite, called its ignition temperature. If the material is below this temperature, it will not catch fire, even if it is surrounded by oxygen. For example, wood will only burn when heated sufficiently.
Imagine trying to start a barbecue. You can’t just throw wood on the grill; you need to reach a high enough temperature (adding lighter fluid or paper) to ensure the wood ignites.
Signup and Enroll to the course for listening the Audio Book
Inflammable substances have very low ignition temperature.
Inflammable substances ignite easily because they catch fire at low temperatures. This is important for safety reasons, as these materials pose a significant risk of accidental fires.
Think about how quickly gasoline can ignite compared to a piece of wood. Gasoline is highly flammable (or inflammable), which is why it should be stored safely far from any heat source.
Signup and Enroll to the course for listening the Audio Book
Fire can be controlled by removing one or more requirements essential for producing fire.
Fires can be extinguished by removing one of the three essential components: fuel, oxygen, or heat. This is the principle behind fire-fighting techniques. For example, throwing water on a fire cools the material below its ignition temperature.
If you observe a campfire, you can see how adding logs keeps it burning (fuel). If you throw dirt on it (removing oxygen), the fire will die out.
Signup and Enroll to the course for listening the Audio Book
Water is commonly used to control fires.
Water is effective in putting out fires that involve solid fuels like wood because it cools down the burning material and may also cut off the oxygen supply by creating steam. However, it's not suitable for all types of fires, such as oil fires.
If you’ve ever spilled oil in a kitchen, pouring water on it might actually make it worse because oil floats on water. Instead, using a fire extinguisher that releases carbon dioxide would be safer and more effective.
Signup and Enroll to the course for listening the Audio Book
There are various types of combustions such as rapid combustion, spontaneous combustion, explosion, etc.
Combustion can occur in several ways, such as rapid combustion (like a fireworks explosion), spontaneous combustion (where a material ignites on its own due to heat accumulation), and explosive combustion (where a rapid reaction occurs with a loud noise). Different scenarios and materials lead to different combustion types.
Think of how a firecracker works: it doesn’t gradually burn like a candle; it explodes with a bang due to a rapid and uncontrolled combustion reaction.
Signup and Enroll to the course for listening the Audio Book
There are three different zones of a flame - dark zone, luminous zone and non-luminous zone.
A flame has several zones: the dark zone (where incomplete combustion occurs), the luminous zone (glowing yellow part due to carbon particles), and the non-luminous zone (outermost blue part where complete combustion occurs). Each zone has different temperatures and combustion characteristics.
When you cook, the blue part of your stove flame is very hot (ideal for cooking), while the yellow part of a candle is cooler and produces more soot. This is why sometimes we see blackened pots from cooking techniques.
Signup and Enroll to the course for listening the Audio Book
An ideal fuel is cheap, readily available, readily combustible and easy to transport. It has high calorific value. It does not produce gases or residues that pollute the environment.
An ideal fuel is one that meets all the best requirements for ease of use and efficiency. It should not only provide a lot of energy but also be safe for the environment and economical. Unfortunately, no fuel meets all these criteria perfectly.
Think of how gas (LPG) is considered a good fuel. It burns cleanly without producing much smoke, making it quite ideal for domestic cooking compared to burning wood.
Signup and Enroll to the course for listening the Audio Book
Fuel efficiency is expressed in terms of its calorific value which is expressed in units of kilojoule per kg.
The calorific value indicates how much energy a fuel releases when burned. It's measured in kilojoules per kilogram (kJ/kg). Higher calorific values mean that the fuel is more efficient and burns hotter, requiring less fuel to produce the same amount of energy.
When you compare different types of fuels for a barbecue, you’d notice that some, like charcoal, produce a lot more heat than, say, wood shavings. Thus, less charcoal is needed to achieve the same cooking temperature.
Learn essential terms and foundational ideas that form the basis of the topic.
Key Concepts
Combustion: The process of burning that requires fuel, oxygen, and heat.
Ignition Temperature: The minimum temperature required for a substance to catch fire.
Types of Fuel: Solid, liquid, or gaseous materials used for energy.
Environmental Impact: The negative effects of combustion on air quality and climate.
See how the concepts apply in real-world scenarios to understand their practical implications.
Burning wood in a fireplace is an example of combustion where heat and light are released.
LPG used in cooking stoves burns rapidly, demonstrating rapid combustion.
Use mnemonics, acronyms, or visual cues to help remember key information more easily.
To burn you need three, it's clear to see, fuel, heat, and air, and then you'll be free.
Imagine a traveler needing fire. They gather wood, find a match, and know to blow gently to provide air. The warmth of the flame shows how combustion is alive!
F.O.H: Fuel, Oxygen, Heat - the Three Musketeers of combustion!
Review key concepts with flashcards.
Review the Definitions for terms.
Term: Combustion
Definition:
Chemical process where a substance reacts with oxygen to produce heat and light.
Term: Ignition Temperature
Definition:
The minimum temperature at which a substance begins to burn.
Term: Fuel
Definition:
Substance that burns to produce energy.
Term: Inflammable
Definition:
Substances that ignite easily at low temperatures.
Term: Calorific Value
Definition:
Amount of heat energy produced by the complete combustion of 1 kg of fuel.
Term: Global Warming
Definition:
Increase in Earth's average temperature due to greenhouse gases.