Make Bubbling, Spooky Halloween Cauldrons with Dry Ice
posted by: Susan Wells
I have never been much of a Halloween fan, but after working with Steve Spangler for more than eight years, Halloween has become one of my favorite holidays. I had no idea you could have so much fun with dry ice and warm water. If you are planning a Halloween party this season at home or helping plan a school party, dry ice is a must to create oozing and bubbling fun.
I have brought the following demonstrations into my daughter’s classrooms and performed them at Halloween parties for the past few years. I love to do these activities to watch the excitement and wonder in the children’s eyes. Okay, I also love it myself. The kids give me the excuse to play.
First, some background information on dry ice.
Dry ice is frozen carbon dioxide. It doesn’t melt; it turns, instead, into carbon dioxide gas. Dry ice is extremely cold – 110F (-78 C). It can cause severe burns if it comes in contact with skin, so make sure to use gloves or tongs when handling it. When dry ice is dropped into water, carbon dioxide gas and water vapor are released as the dry ice “melts” in the water. The gas you see are tiny water droplets.
Where Can I Buy Dry Ice?
Before you can do any of the activities, you need to head to your local grocery store for dry ice. Not all grocery stores sell dry ice, so you may need to call around. Take a cooler and gloves with you to transport the dry ice home safely. Dry ice sells for around $1 a pound. If you are going to do several demonstrations, plan to purchase around 5 to 10 pounds.
Dry Ice Storage and Safety
Store the dry ice in your cooler, not fridge or freezer. It is at a lower temperature than your freezer and can lower the temperature in the freezer causing it to shut off. Or the dry ice may turn into a gas. The gas can build up inside the freezer and will eventually pop the door open. When doing your demonstrations, keep the dry ice in a closed cooler. I like to keep it on the floor behind my feet. The children (and any adults) will rush the table you are working on and do their best to be the closest to the demonstration. When I have done these activities for my daughter’s classes, I have been surrounded every time. It’s important to keep the dry ice in a safe place. Also keep a small hammer on hand to break apart the blocks of ice.
Disappearing Dry Ice
This is a good demonstration to show why it’s called dry ice. Take two plates, place a regular ice cube on one, and a piece of dry ice on the other. Keep both plates out of reach of the children. Ask the children what they think will happen to both ice cubes if left out. Check back in about an hour. The water ice cube will be a puddle of water. The dry ice cube plate will be empty. What happened to the dry ice? It’s made from some of the air that we breathe… it’s frozen carbon dioxide. The dry ice turned into invisible carbon dioxide gas that disappears into the air.
You will need a bowl or tall glass filled with warm water for this activity. I like to use graduated cylinders. They are tall, durable and not wide enough to allow a child to put their hand down inside and accidentally touch the dry ice. This is important, as the children will want to touch the water and vapor. Using gloves or tongs, place a piece of dry ice in the warm water. The dry ice will begin to turn into carbon dioxide gas and water vapor. The cloud is safe to touch, just don’t allow the children to put their hands near the dry ice. When the water cools down and the smoke slows down, replace the cold water with warm and add more dry ice. And yes, you will get cheers of “do it again!”
- Add a squirt of liquid dish soap like Dawn or Joy to your warm water and dry ice concoction. The soap in the water traps the carbon dioxide and water vapor in a bubble. The children will erupt into oohs and ahhs when they see the bubbles climb out of the cylinder of warm, soapy water and explode with a burst of “smoke” as they crawl over the edge. The children won’t be able to keep their hands away.
- Add a squirt of food coloring or tub tints to the water to make the demonstration more colorful. I love to do this. I set up three or more cylinders with different colors and let them go. This helps if you have a larger group allowing for 3-5 kids at each cylinder. Just make sure you have adult supervision at each station so cylinders do not get dumped over.
- To give the water an eerie glow, add a light stick in the water and turn off the lights.
- Put the dry ice and warm water in a dish and set it inside your jack-o-lantern.
Carbonate Apple Juice for Witches’ Brew
Fill a bowl or cauldron with apple juice. Use gloves or tongs to add a few large pieces of dry ice. Let the children watch the mixture bubble and burp as it gets carbonated by the dry ice. Wait until the dry ice is completely gone before serving the apple juice.
For more information on dry ice and for more activities head over to Steve Spangler Science.