School science experiments
Purple Flame Magic
Materials
5g of pottassium permanganate cystals, 2ml of glycerol, a
porcelain tile and a dropper.
Procedure
Pile 5g of powdered KMnO4 crystals on a porcelain tile.Make a small
depression on the centre of the pile. Using a dropper or a glass tube add carefully
about 3 to 4 drops of glycerine to the depression.
After a few seconds a white puff of smoke is produced followed by sparks and purple
flame.
Discussion
This experiment demonsrtates spontaneous combustion. KMnO4
oxidizes glycerol exothermically producing heat and light.
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Praveen Kamath Sir, GHS Ankanahally, Somavarpet Taluk, Kodagu
Soap hating and sugar loving match sticks
Materials
A bowl with water, match sticks, sugarlump, soap piece.
Procedure
Arrange the match sticks (about 6 of them)in the bowl of water leavinf space between the ends about the size of a rupee coin.
Place a small piece of soap with a stick at the center. The match sticks run away to the sides of the bowl showing they hate the soap.
Remove the soap piece and place a lump of sugar at the center of the bowl. All the match sticks will come to the center showing they love sugar.
Discussion
Soap contains long chain sodium salt fatty acids which are hydrophobic and repelled by water molecules.So the sticks go away to the sides.When sugar is placed in the bowl the water molecules dissolve the sugar particles and their attraction causes the match stiks to come close to one another.
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Praveen Kamath Sir, GHS Ankanahally, Somavarpet Taluk, Kodagu
Coin Challenge
Materials
Dinner plate or glass plate, coin, glass tumbler,candle match box and cork.
Procedure
Pour some water in the dinner plate and place a coin in it. Fix a candle piece to the cork and place it above the water level in the plate. Light the candle with a match stick and invert a glass tumbler on it carefully.The candle continues to burn with the dull flame and after sometime it is extinguished. The waterfrom the plate rushes inside the tumbler leaving the coin behind. The coin can be picked with hand and shown to the audience.
Discussion
The burning candle takes up the oxygen from the air in the tumbler for burning. Once oxygen supply is finished it gets extinguished. Due to consumption of oxygen the water is sucked inside. The coin becomes free from water.
Caution:
Do not add too much water.
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Praveen Kamath Sir, GHS Ankanahally, Somavarpet Taluk, Kodagu
Magical Wand of Fire
Materials
5g of KMnO4 crystals , 5ml of conc.H2SO4 , 10 ml of ethyl alcohol, glass rod and porcelain tile.
Procedure
Spread powdered KMnO4 crystals on the surface of the porcelain
tile. (Do not make big piles) Moisten the crustals with conc.
H2SO4 by dropping small drops of acid carefully.
Dip a glass rod in ethyl alcohol taken in a test tube. Remove the glass rod and carefully bring it in contact with the pile on the tile.
Flame errupts and it cab be seen on the glass rod as well as on the top of tile.
The experiment can be shown number of time with other portions of the tile.
Discussion
KMnO4 is a powerful oxidiing agent . It oxidizes ethyl alcohol and the heat liberated makes the remaining alcohol to catch the fire.
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Praveen Kamath Sir, GHS Ankanahally, Somavarpet Taluk, Kodagu
