Chemical Mystery #5: How to burn water

The video below displays a neat trick you can do for your students. What do you suppose is the secret behind this trick? Hint: It has to do with chemistry!


Once you think you know the answer - Check out the SOLUTION!



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Demonstration videos presented here are not meant as tools to teach chemical demonstration techniques. They are meant as a tool for classroom use. The demonstrations may present safety hazards or show phenomena that are difficult for an entire class to observe in a live demonstration.

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Comments 1

Andres Tretiakov's picture
Andres Tretiakov | Mon, 07/13/2015 - 02:53

Hi Tom,


I'm thinking there are a few drops of a flammable hydrocarbon already inside the flask. Possibly hexane or naphtha derivative or some other with a high carbon content and very high vapour pressure or volatility. Most important it is immiscible with water and less dense. So, when you add the water the drop and vapour floats on it and you are able to ignite it.

Is this correct?


As always great way to initiate a discussion on the subject.


All the best,


P.S.: the cysnotype print t-shirt will be ready soon.