Final Paper

Do you like to blow things up? I think explosions are fun. I come up with random questions all the time, and recently I was wondering...can you explode a watermelon with dry ice in a water bottle? I’ve been wondering this for a while now, and I specifically want to know if the size or thickness of the water bottle affects the outcome or reaction. To find this answer, I’m going to conduct an experiment. How will I do this? I will be taking a watermelon, and using the dry ice in a water bottle to burst the large fruit into a million pieces. I am going to test and see how the ice reacts to 2 different sized bottles. I want to see if size or density of the water bottle matters, so I will use a small, decently thick water bottle, a large thin water bottle, and a large thick water bottle. I will also try 2 different ways to put the dry ice in the bottle. I am working with a partner. My partner, Emma Holder, is going to find out how to explode the watermelon and why it explodes like it does. Together, I think we have a super cool project!

Before we learn about how to explode objects with dry ice, we need to grasp a better understanding of what dry ice really is. Dry ice was discovered by a French chemist, named Thilorier, in 1835. When he opened a cylinder of liquid carbon dioxide to observe it, he saw a solid block of dry ice at the bottom. Thus block was created because a decent amount of the liquid had evaporated. (Ackerman)

“Dry ice” may sound confusing, considering the fact that ice is frozen water, and water is a liquid. Dry ice does not melt at room temperature like regular ice would. Dry ice goes through a process called sublimation, which is when something passes straight from a solid form to a gas. (Breau)

Dry ice is extremely cold. Usually it is used for freezing/keeping things frozen. It is exactly -109.3℉ or -78.5℃ (Ackerman). Dry ice is widely used in keeping things frozen for long periods of time (Ackerman). There are also many other uses for dry ice, such as dry ice blast cleaning, which is a cleaning process that uses small, dense pellets and dry ice blocks to clean machines and more (“Dry Ice Uses”). Also, you can make a cool dry ice fog effect by putting hot water into a large bowl and gently putting the dry ice into it (“Dry Ice Uses”). Hunters and fishers use dry ice too, to freeze the meat (‘Dry Ice Uses”).

Dry ice is extremely dangerous. You should never let your skin make contact with it. If you do ever touch dry ice, your skin cells will die, creating a dry ice burn (Helmenstine). When handling dry ice, it is a good idea to use tongs when coming in contact with it (Helmenstine). It only takes a few seconds for the dry ice to burn you, so many safety precautions must be taken, such as wearing thick gloves and face-guards. You should also make sure to wear jeans and closed-toed shoes, just to make sure you don’t get hurt.

When dry ice sublimates, its produces carbon dioxide gas. Carbon dioxide is not toxic, but it reduces the amount of oxygen in the air, making it hard for you to breathe. Dry ice can be extremely dangerous to one’s health if handled in an enclosed area. (Helmenstine)

Now that we have a better understanding of what dry ice is and how it is handled, we are ready to begin the experiment. To begin, I set up a simple and short materials list:

  • 10 pounds of dry ice
  • 1 liter empty bottle with a cap (flimsy)
  • 1 liter empty bottle with a cap (sturdy)
  • 2 small, empty juice bottles
  • 2 watermelons
  • Safety gear (face guard, rubber gloves)
  • Large knife
  • Hammer
  • Tongs

Once I had gotten all of the materials i needed to conduct the experiment, I set one of the watermelons vertically on the table in the backyard, and began to cut a hole into it. The hole was pretty big, considering the fact that I was using the big water bottle, and it had to fit all the way into the watermelon. Next, I put on my face guard and my gloves. Then I took the block of ice that i had bought from a local grocery store, and smashed it into tiny pieces with a hammer. After that, I filled the liter bottle about ⅘ to the top with room-temperature water, and placed it in the watermelon, which by now I had moved to a spot in the grass, far away from the house. Next, i took the small dry ice pieces and used tongs to quickly and carefully put about 6 or 7 pebbles of the ice into the water.

By this point, the water was, what seemed to be, boiling. I quickly screwed the cap on tightly, and ran about 30 feet from the watermelon, so I would not get hit by any of the flying melon pieces. It took about 10-15 seconds of straight suspense, but then it exploded with a loud crackle noise. Watermelon juice ended up traveling about 50 feet, but the watermelon pieces themselves only traveled 5 feet at most.

Then, I tried the explosion with the smaller bottles, and reversed my steps. First I put the dry ice into the bottle, then I poured water in it. Next I screwed on the cap and ran, just as I had done before. But this time, I waited 5 minutes for an explosion, and nothing ended up happening. So, I looked at what was going on, and in the bottle, all the water had frozen.

Apparently, pouring the water into the bottle before adding the dry ice transfers the kinetic energy from the water into the dry ice, making the sublimation process faster. The gas builds up and so does a high amount of pressure. When the pressure gets high enough, the bottle explodes, therefore exploding the watermelon. But when the process is reversed, and you pour the water onto the dry ice, the water is instantly frozen, and no pressure is built up.

Overall my question was answered. You cannot reverse the process, and there is only one way you can do this experiment. It was fun to blow up watermelons with my partner emma. The project was a success. It was very easy to accomplish and a lot of fun to do.




Works Cited


Ackerman, Ken. “History of Dry Ice.” Dry Ice Info, 21 Feb. 2013, dryiceinfo.com/history.htm. Accessed 8 Feb. 2017.

Brain, Marshall. “What if I Touched Dry Ice?” How Stuff Works, 24 Mar. 2008, science.howstuffworks.com/touched-dry-ice.htm. Accessed 8 Feb. 2017.

Breau, Amy. “Why is Dry Ice Dry?” Moment of Science, 31 May 2011, indianapublicmedia.org/amomentofscience/dry-ice-dry/. Accessed 8 Feb. 2017.

Howard, Brian. “The Science of Dry Ice Bombs, Like LAX’s.” National Geographic, 17 Oct. 2013, news.nationalgeographic.com/news/2013/10/131015-how-dry-ice-bombs-work/. Accessed 8 Feb. 2017.

Rich, Brian. “Experimenting With Dry Ice.” Brian Wesley Rich’s Science Website, 1 July 2011, www.west.net/~science/co2.htm. Accessed 8 Feb. 2017.

Helmenstine, Anne. “Why is Dry Ice Dangerous?” About Education, 9 Oct. 2016, chemistry.about.com/od/dryice/f/Why-Is-Dry-Ice-Dangerous.htm. Accessed 17 Feb. 2017.

“Dry Ice Uses.” Allied Refrigeration Co., 2017, dryicekc.com/dry-ice-uses/. Accessed 23 Mar. 2017.