Finally, students observe the increase in temperature that occurs when the reaction rate of an exothermic reaction is increased. All 5 demonstrations require a total of approximately 15 minutes of preparation and can be performed in approximately 20 minutes.
Then, observe a color change that confirms the presence of a reducing agent in the glow stick.
Uses[ edit ] Glow sticks are waterproof, do not use batteries, generate negligible heat, are inexpensive, and are reasonably disposable. By mixing the peroxide with the phenyl oxalate ester, a chemical reaction takes place, yielding two moles of phenol and one mole of peroxyacid ester 1,2-dioxetanedione.
Lyons listed as the inventors Patent 3, The same effect can be achieved by adding copious amounts of sodium salicyate or other bases. It is rarely used, as it breaks down in contact with CPPOshortening the shelf life of the mixture.
They are used as light sources and light markers by military forcescampersand recreational divers. Manipulating the reaction rate of the glow stick components by varying the temperature and the pH can increase or decrease the intensity of light produced, and students use their understanding of reaction rate mechanisms to explain these results.
Learn how to distinguish between chemiluminescence and fluorescence. At maximum concentration typically only found in laboratory settingsmixing the chemicals results in a furious reaction, producing large amounts of light for only a few seconds. The chemicals inside the plastic tube are a mixture of the dye, the base catalyst, and diphenyl oxalate.
The reaction between the two chemicals is catalyzed by a base, usually sodium salicylate. They can tolerate high pressures, such as those found under water.