COAL AND PETROLEUM
Introduction
We use different kinds of materials as fuels for various purposes at home.You might have observed or heard about how people used to burn wood, coal, cakes of cow dung, kerosene etc., for cooking food at home. Blacksmiths in
villages also use them for heating metals. Both in urban and rural areas, now a day’s, LPG is used as fuel for cooking the food.We use the light from the burning candle or kerosene lamp, when there is no supply of electricity. You might have also observed burning of a candle or coal. What difference do you notice in the burning process?
• Why does candle give flame when it is burnt but why does coal burn without emitting a flame ?
• Do all fuels produce same amount of heat when they are burnt?
• What do we need to burn a material?
• Have you ever tried burning a piece of paper or wood or coal, a small rock or a pebble?
• Do all of them burn?
Let us do an activity to know which of these materials burn and which do not.
Do all materials burn ?
You will need a pair of tongs, somemetal or clay dishes and a candle or a spirit lamp.Using tongs, pick up a small piece of paper and bring it close to the lighted spirit lamp and keep it on flame
Carry out this experiment with a piece of charcoal, magnesium ribbon, straw, cotton cloth, nylon cloth, dry wood, pebble, wax, plastic piece etc, and record your observations.You can also try to burn liquids.
Take 2mL of water in small plate. Bring lighted stick near to water in the plate