Combustion and Flame, activities,

1. DELHI TEACHERS’ TRAINING
COLLEGE
DEENPUR, NAJAFGARH, NEW DELHI – 110043
(Affiliated to G.G.S.I.P. University, Delhi – 110075)
B.Ed. 2015 – 2017
Semester - III
Submitted By:-
Swati Ghansela
Enrollment No.-
05940202115

2. MULTIMEDIAMULTIMEDIA
LESSON PLANLESSON PLAN
(Combustion and Flame)(Combustion and Flame)

3. General Objectives:-
i) To enable the students to understand the concept of Science
ii) To develop the logic and reasoning power of the students
iii) To arouse the interest of the students in the quantitative side of the world
Specific Objectives :-
1.Cognitive domain
(a) Knowledge level
The students will be able to
i. define combustion
ii. list the types of combustion
(b) Understanding level
The students will be able to
i. explain the process of combustion
ii. Understand the combustible and non combustible substances
Name of the School: BVM Public School
Class: 8th
Subject: Science
Lesson Plan
Topic: Combustion and Flame

4. (c) Application level
The students will be able to illustrate the types of combustion with example
(2) Affective Domain
The students will be able to acknowledge and associate the learning with real life.
(3) Psychomotor Domain
The students will be able to write the conditions of combustion.
Statement of Aim:-
Today we are going to study the concept of combustion and flame
Teaching Aid:-
 Power point presentation
Previous Knowledge:-
 Students are aware of fire
Recapitulation:-
Q1. What is combustion?
Q2. Explain fire.
Homework:-
Q. Write some combustible and non combustible substances.

5. Combustion
 A chemical process in which a substance reacts with oxygen to give off heat is called
combustion.
 The substance which undergoes combustion is called a combustible substance. It is also
called a fuel.
 Sometimes light is also produced during combustion either as a flame or as a glow.
 Air is necessary for combustion.

6. Types of combustion
There are three main types of combustion. They are :-
•Rapid combustion
•Spontaneous combustion
•Explosion
Rapid combustion:- is combustion in which a substance burns rapidly and produces heat
and light with the help of external heat.
Example:- burning of LPG.
Spontaneous combustion:- is combustion in which a substance burns spontaneously and
produces heat and light without the help of external heat.
Example:- phosphorus burns spontaneously at room temperature.
Explosion:- is a combustion in which a substance burns suddenly and produces heat, light
and sound with the help of heat or pressure.
Example:- explosion of crackers on applying heat or pressure.

7. Types of Combustion
Rapid combustion
Spontaneous combustion
Explosion

8. Ignition Temperature
 The lowest temperature at which a substance catches fire is called
its ignition temperature.
 combustible substance cannot catch fire or burn as long as its
temperature is lower than its ignition temperature.
 Kerosene oil and wood do not catch fire on their own at room
temperature. But, if kerosene oil is heated a little, it will catches
fire.

9. Combustible substances
Substances which burn in air to produce heat and light are called combustible substances.
Example :- wood, coal, charcoal, kerosene, petrol, diesel, liquefied petroleum gas (LPG),
compressed natural gas (CNG) etc.
Wood Coal LPG kerosene

10. Non-combustible Substances
 Any material that does not readily burn. For everyday use, most metals, rock, and
glass are non-combustible.
 Drywall (sheetrock is a brand name) is made from gypsum rock, and is
considered non-combustible- as is brick and concrete. Asbestos is very
thoroughly non-combustible, but rarely used any more due to severe health hazards.
3 examples of non-combustible substances are rock, steel and water, sand etc.

11. Activity: Combustible and Non
Combustible
Material Combustible Noncombustible
Wood
Paper
Iron nails
Kerosene oil
Stone piece
Straw
Charcoal
Matchsticks
Glass

12. Air is necessary for burning
(A) (b) (c)
• Fix a lighted candle on a table. Put a glass chimney over the table and rest it on a few wooden
blocks in such a way so that air can enter the chimney. Observe what happens to the flame.
• Now remove the blocks and let the chimney rest on the table. Again observe the flame.
• Then put a glass plate over the chimney. Observe the flame again.
• The candle burns freely in (a) because air enters the chimney from below.
• The candle stops burning in (b) because air does not enter the chimney from below.
• The candle does not burn in (c) because air is not available.
• This shows that air is necessary for burning.

13. Activity Demonstration
Candle Activity

14. Ignition Temperature
• The minimum temperature at which a substance catches fire and burns is called its
ignition temperature.
• A substance will not catch fire and burn if its temperature is lower than its ignition
temperature.
• Different substances have different ignition temperatures.
• Example:- the ignition temperature of kerosene is less than the ignition temperature of
wood.
• Substances which have very low ignition temperature and can easily catch fire with a
flame are called inflammable substances. Eg:- petrol, alcohol, LPG, CNG etc.

15. Inflammable Substances
 The substances which have very low ignition temperature and can
easily catch fire with a flame are called inflammable substances.
 Examples of inflammable substances are petrol, alcohol, Liquefied
Petroleum Gas (LPG).
Conditions necessary for combustion
 The conditions necessary for combustion are :-
I. Fuel.
II. Air (to supply oxygen).
III. Heat (to raise the temperature beyond the ignition temperature.
A substance will not burn without one or more of these conditions.

16. How do we control fire ?
The conditions necessary for producing fire are :-
I.Fuel
II.Air (to supply oxygen)
III.Heat (to raise the temperature of the fuel beyond its ignition temperature).
Fire can be controlled by removing any one or more of these conditions.
A fire extinguisher cuts off the supply of air or brings down the temperature of the fuel
or both and controls the fire.

17. Methods of controlling fire
I) by using water :-
water is the most common fire extinguisher. It can be used only when materials like wood
, paper etc. Are on fire.
Water cannot be used if electrical equipment's are on fire because water conducts
electricity and can harm those trying to put out the fire.
Water cannot be used to put out oil and petrol fires because they float on water and
continue to burn.
Ii) by using carbon dioxide:-
Carbon dioxide is the best fire extinguisher to put out fire caused by inflammable materials
like oil and petrol and electrical equipments. Carbon dioxide is heavier than air and it covers
the fire and cuts off the supply of oxygen and puts out the fire.
Carbon dioxide is stored at high pressure as liquid in cylinders. Chemicals like sodium
bicarbonate (baking soda), potassium bicarbonate produce carbon dioxide near the fire.

18. Chemicals used to turn off Fire

19. Video of methods of controlling fire

20. Flame
 A flame is the visible, gaseous part of a fire. It is caused by a
highly exothermic reaction taking place in a thin zone.
 Very hot flames are hot enough to have ionized gaseous
components of sufficient density to be considered plasma.

21.  The substances which vaporise during burning, give flames.
 For example, kerosene oil and molten wax rise through the wick
and are vaporised during burning and form flames.
 Charcoal, on the other hand, does not vaporise and so does not
produce a flame.
Structure of a Flame

22. What is a Fuel?
 The sources of heat energy for domestic and industrial purposes
are mainly wood, charcoal, petrol, kerosene, etc. These substances
are called fuels.
 A good fuel is one which is readily available.
 It is cheap.
 It burns easily in air at a moderate rate.
 It produces a large amount of heat. It does not leave behind any
undesirable substances.
 There is probably no fuel that could be considered as an ideal fuel.
 Some fuels are cheaper than others.

23. Fuel Efficiency
 The amount of heat energy produced on complete combustion of 1
kg of a fuel is called its calorific value.
 The calorific value of a fuel is expressed
in a unit called kilojoule per kg (kJ/kg).
Fuel Calorific Value
(kJ/kg)
Cow dung cake 6000-8000
Wood 17000-22000
Coal 25000-33000
Petrol 45000
Kerosene 45000
Diesel 45000
Methane 50000
CNG 50000
LPG 55000
Biogas 35000-40000
Hydrogen 150000

24. Burning of Fuels Leads to Harmful
Products
 1. Carbon fuels like wood, coal, petroleum release unburnt carbon
particles. These fine particles are dangerous pollutants causing
respiratory diseases, such as asthma.
 2. Incomplete combustion of these fuels gives carbon monoxide
gas. It is a very poisonous gas. It is dangerous to burn coal in a
closed room. The carbon monoxide gas produced can kill persons
sleeping in that room.

25. Global Warming & Acid Rain
 Combustion of most fuels releases carbon dioxide in the
environment. Increased concentration of carbon dioxide in the air
is believed to cause global warming.
 Burning of coal and diesel releases sulphur dioxide gas. It is an
extremely suffocating and corrosive gas. Moreover, petrol engines
give off gaseous oxides of nitrogen. Oxides of sulphur and
nitrogen dissolve in rain water and form acids. Such rain is called
acid rain. It is very harmful for crops, buildings and soil.
Precaution To Be Taken
 The use of diesel and petrol as fuels in automobiles is being
replaced by CNG (Compressed Natural Gas), because CNG
produces the harmful products in very small amounts. CNG is a
cleaner fuel.