Magic Density Rainbow Experiment
Alrighty, so this is an experiment that I did in the lab last semester. It is fun, easy, and sure to please. We made a pot of gold!...errrr well, we made the rainbow that should lead to the pot of gold.
This experiment is dubbed, The Density Rainbow
- 5 Test Tubes/ Glasses
- Food Color
- First off, you need to line up all five of your glasses. Leave the first glass empty for now. In the other four glasses add sugar. One tablespoon in one, then two in another, then three in another, and then four. Now that you have a different amount in each, we shall proceed.
- Put 60ml of water (about 4 tablespoons) into the four glasses that contain sugar. Make sure to totally dissolve the sugar in the water.
- In the glass with one tablespoon, add 2-3 drops of red food coloring. In the second, add yellow, then green, and lastly blue.
- Rainbow time! Add the blue mixture into the empty glass. Carefully add the green. Add it by using a pipette and adding the solution just above the blue layer slowly. Or you can use a spoon and slowly pour the liquid over the back of the spoon, very slowly as to not disturb the blue layer. Do this till your glass/test tube is half full.
- Add the yellow in the same manner till about 3/4th full.
- And lastly, you can slowly add the red mixture till the glass is full. And Voila! A rainbow!
But, alas, this rainbow will not stand the test of time. This solution is miscible and will blend eventually.
The Chemistry Behind it
So, why does this occur? Well, each solution has a different density. The more dense the solution, the more likely that it will float. So the denser solution of sugar water floated on top of the less dense.
Now, I only used four colors, but feel free to try to use more. It just becomes a little harder to keep the colors from mixing, but it can be done.