Thursday, May 10, 2018

redox - Why do gummy bears explode when added to hot potassium chlorate?


This link shows that a gummy bear explodes when in contact with heated potassium chlorate, KClOX3. But what in a gummy bear creates this reaction?


Also, do other foods (fruit, icing sugar...) react as violently with potassium chlorate?


Gif of gummy bear explosion



Answer



Potassium chlorate is a source of oxygen. After heating, it decomposes to OX2 and KCl: 4KClOX3KCl+3KClOX4

KClOX4KCl+2OX2


The gummy bear is mainly composed of sugar and other carbohydrates. Those carbohydrates will react with oxygen, combustion occurs. For example, glucose will react in this manner: 6OX2+CX6HX12OX66COX2+6HX2O


If there is any material present which does not burn, such as HX2O, the temperature will not rise as high. For gummy bears the reaction works spectacularly because they are mainly carbohydrates (>70%).


An apple, for example, has only ~13% carbohydrates – unless you dry it, of course. On the other hand, this video on YouTube is an example of how sugar itself reacts violently with potassium chlorate.



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