How does carbon dioxide help in putting off fire ?
Carbon dioxide covers the surface of the burning substance and act as blanket and hence does not allow the oxygen to reach the substance. In absence of oxygen the fire gets put off.
Give reason for the following :
Paper by itself catches fire easily where as a piece of paper wrapped around an aluminium pipe does not.
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.
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 ?
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.
