By Blog Editor Susan Wells
To be the hit of your classroom or home Halloween party, all you need is a chunk of dry ice, some warm water, dish soap and a container. I shared some Halloween science at our Brownie Troop meeting this week. All 17 girls in the troop attended. Nothing like a promise of Halloween science to get everyone to the meeting.
This is the easiest and by far most popular dry ice demo you can do. For our Brownies, I brought Vampire Veins (Insta-Worms), Boo Bubbles and created a few bubbling cylinders to set the mood. I was caught in a crowd of gloved hands as I made Boo Bubbles for several girls. When I was done, I looked over to my cylinders and there was a large group of girls playing with the vapor and bubbles. No matter how many times I set up the Bubbling Cylinders, they are always a huge hit.
- Dry ice
- Dish soap
- Graduated cylinder (or similar container)
- Heavy glove
- Warm water
- Safety glasses
- Fill your graduated cylinder half-full with warm water. If you don’t have a graduated cylinder laying around, you can use something similar, like a flower vase or another tall, narrow container.NOTE: Before handling any dry ice, put on a pair of heavy gloves. Dry ice is so cold (-110ºF/-78ºC) that it will burn your skin!
- Make sure that you have pieces of dry ice that are smalle enough to fit inside your graduated cylinder. If not, put on a pair of safety glasses and use a hammer to break the dry ice into smaller pieces.
- Once you’ve created the small pieces, drop a few into the graduated cylinder. Once in the water, the dry ice will begin bubbling and producing a smoke within the cylinder. Eventually the smoke flows right over the top.
- Take your bubbling, smoking cylinder to a whole new level with… soap? That’s right, just put a squirt of dish soap into the cylinder and watch what happens! Before you know it, a column of bubbles begins to form at the mouth of your cylinder.
- Don’t be afraid, grab those bubbles and give them a squeeze! These bubbles burst with an amazing explosion of fog.
- I also added a few drops of Atomic Glow and set the cylinders next to a black light. The bubbles glowed as they popped and fizzed.
Color Changing Smoking Bubbles
Does dry ice have the power to change the color of liquids? You’ll have to see this experiment to believe it.
- 2 plastic cylinders
- Universal Indicator
- Long spoon or stirring stick
- Gloves / tongs
- Safety glasses
- Household ammonia water
- A few pieces of dry ice
- Put on your safety glasses.
- Fill the plastic cylinder with 400 mL of water.
- Add a teaspoon (about 5 mL) of Universal Indicator or red cabbage juice. Use a long spoon or stirring stick to mix the solution.
- What color is the solution? Be sure to note this before going on to the next step.
- You’ll need several smaller pieces of dry ice for this activity. The dry ice chunks should easily fit into the plastic cylinder.
- Drop several small pieces of dry ice into the graduated cylinder and watch what happens. Within a few seconds, you should see the liquid change color until it finally turns red. What chemical reaction is taking place to make the liquid change color?
- Repeat the experiment in a second plastic cylinder by filling the container with 400 mL of water. Add a very small amount of ammonia water to the water (no more than a teaspoon) and stir. Add a teaspoon (about 5 mL) of Universal Indicator solution and stir. Notice the immediate color change. Why would ammonia water change the color of the water?
- As you did in step 6 above, drop several small pieces of dry ice into the graduated cylinder and watch what happens. Within a few seconds, you should see the liquid go through a wide spectrum of color changes. What chemical reaction is taking place to make the liquid change color?
For the science behind this experiment, visit the Dry Ice Bubbling Acid page.