Ask A Scientist Chemistry Archive

name         Kelly
status       student
age          16

Question -   How do light sticks glow? What chemicals are used?
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Kelly,

The glow stick reaction is an example of chemilumenescence.  The chemical reaction in 
a light stick involves several different steps.  Commercial light sticks holds a 
hydrogen peroxide solution and a solution containing a phenyl oxalate ester and a 
fluorescent dye.  The following is the sequence for the reaction when the solutions 
are combined:

1. The hydrogen peroxide oxidizes the phenyl oxalate ester, resulting in a phenol and 
an unstable peroxyacid ester.
2. The unstable peroxyacid ester decomposes, resulting in additional phenol cyclic 
peroxy conpound.
3. The cyclic peroxy compound decomposes to carbon dioxide.
4. This decomposition releases energy to the dye.
5. The electrons in the dye atoms jump to a higher energy level, then fall back to 
the lower energy level giving off energy in the form of light.


Please remember that a light stick is housing two solutions and is a portable 
chemistry experiment.  The above information is also on howstuffworks.com.

Sincerely,

Bob Trach
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