The substance which is burn in air ( presence of oxygen ) to produce heat
and light are called combustible substance.
• Combustible substance catch fire easily .
• The substance that undergoes combustion is called as combustible
substance.
• It is also called as fuel
• It may be solid, liquid gaseous .
e.g. wood , coal, charcoal, kerosene, petrol , diesel, liquefied petroleum gas (LPG) , compressed natural gas (CNG).
Examples:
1) Wood :
Wood is naturally combustible substance.
It is made up of organic ( carbon based molecule )
It can easily catch fire by using matchstick and produce Smoke.
2) Liquefied petroleum gas :
LPG is a mixture of propane , butane , pentane .
LPG is highly flammable gas it burn rapidly and produce flame .
It is use in cooking
3) Kerosene :
It is a hydrocarbon and extracted from refined petroleum oil
It is pale yellow color oil .
It is use in lamp as a fuel and ignited as a light .
4) Compressed natural gas:
It is a gaseous fuel.
It is mixed easily in air
When it is mixed with air it converted to ignition source and become combustible.
Question:
1) Why some combustible substance burn easily than other ?
– Some combustible substance have low ignition temperature and catch fire easily and some have high ignition temperature can not burn easily . Hence some combustible substance burn easily.
2) Give the name of two combustible substance
– Coal, kerosene
3) The substance undergoes combustion is called ————
– Combustible substance
4) Which of the fallowing is combustible
- a) Paper b) nails c) stone d) sand
– A) paper
5) What is mean by combustible substance ?
– The substance which is burn easily in air to produce heat and light is called combustible substance