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.
No, the petrol will not catch fire. This is because in a closed tank full of petrol, there is no air to support the combustion of petrol. In the absence of supporter of combustion, petrol cannot burn or catch fire.
When a lot of dry powder of a substance X is released over a fire, the fire gets extinguished.
(a) Name the substance X.
(b) How does the substance extinguish the fire ?
(c) Name another substance which behaves like X.
How does carbon dioxide help in putting off fire ?
Give reason for the following :
Paper by itself catches fire easily where as a piece of paper wrapped around an aluminium pipe does not.
What type of combustion is represented by :
(a) burning of white phosphorus in air at room temperature ?
(b) burning of LPG in a gas stove ?
(c) ignition of a cracker ?
(d) burning of coal dust in a coal mine ?
