Rapid oxidation of sugar
with potassium chlorate
|Potassium chlorate (KClO3), just like potassium nitrate (KNO3)is a powerful oxidant. Sugar is a substance that can be easily oxidised.
Mix sugar and potassium chlorate in a test tube. Only small quantities, as pictured on the right, should be used. Use the granulated sugar and not the powdered sugar.
Place the test tube in sand to protect the container from the extreme heat generated.
Place one drop of concentrated sulfuric acid on to the mixture.
When sulfuric acid is introduced heat is created which decomposes
potassium chlorate to produce oxygen according to the equation below.
|View the video on the right
|View the video of a larger scale mixture conducted outdoors producing a volcano effect.
Some of the products of the reaction are shown on the right. Black pieces of carbon can be seen inside the test tube. Other products include carbon dioxide, water and of course heat.
- concentrated sulfuric acid
Mix the sugar and potassium
chlorate in a test tube. Use the granulated sugar and not the powdered
Safety equipment - lab coat and goggles. This demonstration must be performed outdoors or in a well ventilated fume cupboard.
We suspect that chloric acid
(HClO3) is formed when potassium chlorate (KClO3
) and sulfuric acid (H2SO4 ) are mixed. Chloric
acid rapidly decomposes organic material, such as sugar, with the release
of enormous amounts of heat energy.
The heat released from the
above reaction quickly fuels a second reaction given by the equation below.
This reaction gives off even
more energy to the tune of 429 kJ for every mol of sugar that reacts.
The solid carbon (graphite) formed is visible after the reaction has ceased.
5) What is the mass of potassium chlorate that is needed to completely react with 10 grams of sugar?
Continue with the chemistry of matches
Continue with magnesium burning in CO2