Make a Lava Lamp
You can make a simple home-spun lava lamp. It won't look exactly like one of those store bought ones, but it will be a fun project and you will learn a thing or two about chemistry while you're at it!
What You Need
- 16 oz plastic soda bottle, empty and clean.
- Soda bottle cap
- Vegetable oil
- Food coloring
- An Alka-Seltzer tablet
- Flashlight (optional)
What To Do
- Prepare the mixture. Fill the bottle 3/4 full with vegetable oil. Add water to the remainder of the bottle, almost to the top but without overflowing. Drop in 10 drops of food coloring, to make the solution look fairly dark.
- Cut the Alka-Seltzer tablet into 8 pieces. Drop one of the tiny pieces into the oil and water mixture. The mixture will start to bubble.
- Wait until the bubbling stops and add another piece of Alka-Seltzer. Continue, until there is no more Alka-Seltzer left, and the bubbling has completely stopped.
- Screw on the cap of the soda bottle. Tip the bottle back and forth and watch the wave appear. The tiny droplets of liquid join together to make one big lava-like blob.
- Place a strong flashlight or search light under the bottle to illuminate the bubbles for maximum effect.
- This experiment demonstrates some science you already know...oil and water do not mix. Even if you try to really shake-up the bottle, the oil breaks up into small little drops, but the oil doesn't mix with the water. Food coloring only mixes with water. That's why it does not color the oil. In addition, the Alka-Seltzer tablet reacted with the water to make tiny bubbles of carbon dioxide gas. These bubbles attached themselves to the blobs of colored water and cause them to float to the surface. When the bubbles popped, the color blobs sank back to the bottom of the bottle.
- Don't heat the bottle like a normal Lava Lamp.