Elephant+Toothpaste

Allison Stankowicz


 * //__Demonstration__////://** Elephant Toothpaste


 * //__Materials__://**
 * 50-100 ml of 30% hydrogen peroxide solution
 * saturated potassium iodide solution
 * Liquid dishwashing soap
 * Food coloring (blue if possible)
 * Garbage bag
 * 500 ml graduated cylinder
 * Gloves
 * Goggles


 * //__Step by Step Procedure:__//**
 * 1) Put on gloves and safety glasses. Cover table with a garbage bag.
 * 2) Pour 50 mL of 30% hydrogen peroxide solution into the graduated cylinder.
 * 3) Squirt in a little dishwashing detergent and swirl it around.
 * 4) You can place 5-10 drops of food coloring along the wall of the cylinder to make the foam resemble striped toothpaste.
 * 5) Add 10 mL of potassium iodide solution. Do not lean over the cylinder when you do this, as the reaction is very vigorous and you may get splashed or possibly burned by steam.


 * //__Video/Pictures__://** Not available yet.


 * //__Explanation__://** The chemical equation of this reaction is 2 H2O2(aq) --> 2 H2O(l) + O2(g). It shows that hydrogen peroxide breaks down to form water and oxygen, which is what the foam is made of. This is a decomposition reacted. It is called this since there is one product, the hydrogen peroxides, which breaks down or 'decomposes' to make other compounds or elements. You can see this in the equation since there is one compound on the reactant side (the left side) and more than one on the products side (the right side).

The potassium iodide is not in this equation since it is a catalyst. A catalyst is something that is used to make a reaction go quicker. The only reason potassium iodide is in this experiment is to make the reaction go faster. Without the potassium iodide, the reaction would be alot slower, so there would not have been cool foam produced. You would not be able to see the reaction because it was so slow. So what is the dishwashing soap used for? You can see that when the soap is squirted into the hydrogen peroxide, there are bubbles in the soap. These bubbles have oxygen in them, which is needed in the experiment for the reaction to take place. Lastly, the food coloring is not needed in this demonstration. I use it to get the foam a cool blue-green color.


 * //__Practical Applications:__//** You might have already heard of hydrogen peroxide before. It is a household item that is used to clean cuts and scrapes. However, this hydrogen peroxide is a different concentration, which means there is a different ratio of chemicals in it. This one will actually burn your skin if you get it on you, so that is why we use gloves while working with this hydrogen peroxide.

//__**Sources:**__// [|//http://chemistry.about.com/od/chemistrydemonstrations/a/elephanttooth.htm//] []