Have you seen those magical lava lamps that captivate your attention by producing blobby-bubbles that rise and fall over and over again? Yeah, we can make one of those. And we can learn a whole lot about chemical mixtures while we do it.
Ready to make your own lava lamp using the brilliance of chemistry and some easy-to-find household materials? Let’s get started!
Materials You Need:
Clear plastic or glass bottle
Vegetable oil (the cheaper, the better)
Food coloring (if desired)
Alka-Seltzer tablets (or generic equivalent)
- Fill your bottle about 1/3 full of water.
- Add food coloring, if desired. It’s best to have a darker color so you can really see the water “bubbling” through the oil.
- Fill your bottle the rest of the way with oil, being careful to leave at least 2 inches empty at the top.
- Drop in an Alka-Seltzer tablet and watch what happens!
The chemistry behind this experiment is exactly the same as that of the Color Bombs Experiment we did a few weeks ago. Oil and water don’t mix because they are made of different kinds of chemical bonds. Oil is nonpolar while water is polar, which means they will never mix, even when shaken extremely hard. Food coloring dissolves in water (since it is water-based and polar as well), which leaves the oil sitting on top by itself. When you drop an Alka-Seltzer tablet into the bottle, it only reacts in the water layer. Carbon dioxide bubbles are released as it reacts, causing the fun effect of colored water bubbling up through the oil, and then back down again. This reaction will occur for as long as you feed it fresh Alka-Seltzer tablets. After all the tablets have been used and the mixture stops bubbling, you can even store your lava lamp indefinitely for later use. Enjoy!