Overview: This fun and visually appealing experiment demonstrates the principles of liquid density and immiscibility (when two liquids don't mix). You'll create a dynamic, colorful display reminiscent of a lava lamp.
What You'll Need:
- A clear glass or plastic bottle
- Vegetable oil
- Food coloring (your choice of colors)
- Alka-Seltzer tablets or effervescent tablets
- Fill the bottle about 1/4 full with water.
- Pour vegetable oil into the bottle until it's nearly full, leaving about an inch of space at the top.
- Allow the liquids to settle. You'll notice the oil floats on top of the water because it's less dense.
- Add several drops of food coloring. The drops will pass through the oil and mix with the water below.
- Break an Alka-Seltzer tablet into smaller pieces and drop one piece into the bottle.
- Watch the magic! The tablet will react with the water, producing carbon dioxide gas bubbles that carry colored water upwards, creating a mesmerizing "lava" effect. As the bubbles pop at the surface, the colored water droplets will sink back down.
- Add more tablet pieces to keep the show going!
Science Behind the Fun: The Alka-Seltzer tablet reacts with water to produce carbon dioxide gas. This gas rises, taking some of the colored water with it. Once the gas bubble pops at the surface, the denser water droplet sinks back down through the oil. Additionally, this experiment showcases the immiscibility of water and oil.