Q. 185.0( 3 Votes )
With the help of an experiment, show that air is necessary for burning of a candle.
An experiment to show that air is necessary for burning of a candle is as follows: -
i. At first, light a candle on a table.
ii. A glass chimney is then put over the candle which is being rested on a few wooden blocks in such a way that air can enter the chimney from the bottom.
iii. It will be seen that in this case, the candle burns freely in this case.
iv. In the second set, we had removed the woods and had allowed the chimney to rest on the table.
v. In this case, the flame of the candle flickers and produces smoke.
vi. In the third arrangement, we had put a glass plate over the chimney of the second arrangement above.
vii. In this case, the flame finally goes off.
From the above three experimental setups we can see that the candle burns freely when there was a continuous supply of air as in the first case. The candle started flickering when we had stopped the air supply from the bottom as in the second case. Finally in the third case when we had removed the supply of air from both the bottom and above the candle goes off.
The above observations clearly suggest that air is necessary for the burning of a candle.
Rate this question :
An electric spark is struck between two electrodes placed near each other in a closed tank full of petrol. Will the petrol catch fire. Explain your answer.Lakhmir Singh & Manjit Kaur - Science
Give reason for the following:
Paper by itself catches fire easily whereas a piece of paper wrapped around an aluminium pipe does not.Lakhmir Singh & Manjit Kaur - Science
Which of the following undergoes spontaneous combustion?Lakhmir Singh & Manjit Kaur - Science
What are the conditions necessary for combustion to take place.Lakhmir Singh & Manjit Kaur - Science
Complete the crossword Fig. 6.1 with the help of the clues:
1. Non-metal which catches fire if exposed to air (10) oxygen to give off heat. (10)
3. The lowest temperature at which a substance catches fire is called its __________temperature. (8)
5. The most common fire extinguisher. (5)
2. A chemical process in which a substance reacts with
4. Petrol is used as a __________ in automobiles. (4)
6. It is as hard as stone and black in color. (4)NCERT - Science Exemplar
You are provided with three watch glasses containing milk, petrol and mustard oil, respectively. Suppose you bring a burning candle near these materials one by one, which material(s) will catch fire instantly and why?NCERT - Science Exemplar
Cracker on ignition produces sound. Why?NCERT - Science Exemplar
Give two examples each for a solid, liquid and gaseous fuel along with some important uses.NCERT - Science Exemplar
What makes the middle zone of a candle flame luminous(or light–giving)?Lakhmir Singh & Manjit Kaur - Science
What are non-combustible substance? Name three non-combustible substances.Lakhmir Singh & Manjit Kaur - Science