HARD
8th CBSE
IMPORTANT
Earn 100
A lot of dry powder of one of the following chemicals can be released over a fire to extinguish it. This chemical is :
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Important Questions on Combustion and Flame
MEDIUM
8th CBSE
IMPORTANT
An electric spark is struck between two electrodes placed near each other in a closed tank full of petrol. Will petrol catch fire? Explain your answer.
HARD
8th CBSE
IMPORTANT
Give a reason for the following:
Paper by itself catches fire easily whereas a piece of paper wrapped around an aluminium pipe does not.
HARD
8th CBSE
IMPORTANT
Abida and Ramesh want to heat water taken in separate beakers. Abida kept the beaker near the wick in the yellow part of the candle flame. Ramesh kept the beaker in the outermost part of the flame. Whose water will get heated in a shorter time? Why?
MEDIUM
8th CBSE
IMPORTANT
When a lot of dry powder of a substance X is released over a fire, the fire gets extinguished.
Write the chemical name of the substance X. (Sodium hydrogen carbonate / Sodium carbonate)
HARD
8th CBSE
IMPORTANT
When a lot of dry powder of a substance X is released over a fire, the fire gets extinguished.
How does X extinguish the fire?
MEDIUM
8th CBSE
IMPORTANT
When a lot of dry powder of a substance is released over a fire, the fire gets extinguished.
Name another substance which behaves like .(potassium salt)
(Potassium bicarbonate/Potassium chloride)
HARD
8th CBSE
IMPORTANT
What type of combustion is represented by burning of white phosphorus in air at room temperature? (Spontaneous combustion/ Non-spontaneous combustion)
MEDIUM
8th CBSE
IMPORTANT
What type of combustion is represented by burning of LPG in a gas stove? (Spontaneous combustion/Rapid combustion)
