I know when you think of kids experiments dry ice isn’t the first thing you think of. However, if you take the proper safety precautions, it can be such a great medium for exploration. I was given a large box of dry ice pellets from my sister-in-law. She received some medication enclosed in it and thought instead of throwing it away she would give it to me to use with the boys. I was super excited to research what all we could do with this. To my surprise, it was a big hit with the boys. They used the entire box doing experiments that I had come up with, and some they came up with on their own. This is the stuff I love. When my boys run with something, and you can see their wheels turning. These are the best times we have in learning. Since it was such a big hit with our family, I thought I’d share with you some of the awesome things you can do and learn with such a fascinating compound.
First things first, what is dry ice made of? Dry ice is solidified carbon dioxide. To make it, carbon dioxide is first liquefied under high pressure. The pressure is decreased, which causes some of the carbon dioxide to vaporize. This leads to a drop in temperature that solidifies the remaining carbon dioxide. Dry ice is much colder than regular ice thus you need to take precautions when handling it. I made sure the boys knew the dangers of it, and they were to wear gloves at all times while experimenting with it. Also, because it is so cold it is important that you do not put your face down into the vapors and breathe it in. It will leave you with a very uncomfortable feeling. Dry ice would fall very easily into a lesson on the states of matter: solids, liquids, and gases. Since dry ice is a gas turned liquid and then a solid, it makes for a very interesting compound to discuss.
Now onto the experiments. The first thing to do is put a little dry ice into a bowl. Pour some water over it and watch the reaction. The water will instantly start to bubble, and the vapors will start to roll out of the bowl in a flowing fog. It is really neat as it looks very spooky like you’re in a haunted house. My kids enjoyed doing this in various size vessels as well as trying different water temperatures. They tried it in water bottles, cups, bowls, and a soft drink cup with a straw. It was fun to see the vapors roll out of the straw. One neat thing to try is to make a small hole in the top of a water bottle lid. Put the dry ice in and add water. Quickly screw the lid back on and squeeze the sides of the bottle sharply. The vapors will come out in rings with each puff of the squeeze. It is fun to experiment with different size holes to see what happens to the vapors in comparison.
Now if you don’t mind getting a bit messy you will have so much fun making dry ice bubbles. In a large bowl put a fair amount of dry ice pellets in. Add in some water to get the reaction started. Start blowing bubbles into the dry ice vapors with regular bubbles you can buy at the store. The bubbles will begin to accumulate on the surface of the ice. If you pop these bubbles the vapors will come out in a poof. The boys loved to pop the bubbles to see how fast the vapors would come out. Once the bubbles are covering the top of the bowl leave them sit for a while. Eventually the ones closest to the surface will pop, but the ones on the bottom will be frozen. These can be picked up and handled to observe a bit more closely. The kids had too much fun with these. As I said, it does get messy. You’ve been warned. The bubbles tend to go everywhere.
Another super cool bubble experiment involves using dish soap. In a clean bowl add dry ice pellets. Take a paper towel or thin cloth and dip it into the dish soap. Wipe the top edges all around the bowl with the soap. Now take your towel and cover it completely in dish soap. Add some water to the dry ice to the vapors going. Take your towel and lay it over the bowl sealing the sides down tightly around the bowl. Now, slowly begin to slide the towel over the top of the bowl. As you remove the towel a big bubble will form over the top of the bowl. This may take a few times to get it right but keep trying it is worth it.
One of the boy’s favorite experiments we tried was blowing a balloon up with the dry ice. In a water bottle put some dry ice pellets in and add water. Put the end of a balloon over the top of the bottle and watch it grow. The balloon gets very big with the vapors. Keep watching to see how big it gets before it pops or in our case flew off the top of the bottle and whizzed around the room.
Two other options for observation and discussion are freezing fruit and making silverware sing. We took little piles of ice and put different food items on top. Then we waited to see which item froze the fastest. We tried raspberries, bananas, potato chips, and chocolate. Then we ate them of course as part of our observation. Frozen raspberries were the winner. While you have a pile of ice out take a spoon and sit it on the ice. The silverware will begin to vibrate at such a high speed from the temperature that it will make this ringing sound. This absolutely fascinated the boys. They tried many different items to see if they could get it to create sound as well. It led to great discussions and a lot of exciting experimentation.
I’ve saved the best for last, ice cream. Making ice cream with dry ice is super easy and fun to make. If you’ve ever had nitro ice cream, it is very similar. In a bowl mix up: 1 cup of milk, 1 can of condensed milk, 1/2 cup of sugar, and 2 teaspoons of vanilla extract. In a plastic baggie put in a fair amount of dry ice pellets. Crush the pellets with a meat tenderizer or the bottom of a glass. Begin to slowly add in the crushed dry ice to the mixture and stir at the same time. You have to move quickly in this process as the mixture will begin to freeze almost immediately. Keep adding in the dry ice and mixing until you have a nice consistency. Then spoon it into bowls and add your favorite toppings. That’s it! Another experiment and a tasty treat at the same time.
There are so many other ways to use dry ice in your science lessons, but I am going to stop here. I could write an entire book on it if you let me. I hope that your kids will enjoy dry ice as much as we did. It really is a fun way to spice up a science lesson and get some hands-on learning in there. Let me know if you come up with any other experiments to try with dry ice. It has become a favorite around here, and I see a lot of it in our future. Remember, science is fun, you just have to get creative with it.
-Nicole