Booby traps and pranks have always had a close place to my heart. As a child, I was always a victim of my father’s pranks, for example turning on the sink to find that the sprayer trigger has been tapped down. When I began this assignment, I thought it would be the perfect opportunity for me to step into my father’s shoes and create a diet coke and mentos booby trap. However, considering the goal of this assignment was to step outside of my comfort zone, I decided to take the idea a little further and create a diet coke and mentos rocket. Initially, my hesitation with this idea stemmed from the fear of failure. As you can imagine, this idea is not new. There are many viral videos of people attempting to make a diet coke and mentos rocket and many of those videos end in a messy disaster, some including injury. Nevertheless, I put those fears aside and decided to have fun.
There are many videos on the internet about the diet coke and mentos reaction and a considerable amount of how-to forums and articles that discuss the experiment. My inspiration to create a rocket actually came from a video of a guy who accidentally sends the coke bottle flying in the direction of the camera man.
After dedicating my decision to creating a rocket, my first thought was to find out why and what about this mentos candy and coke drink make such a violent reaction. I felt that if I could understand why the reaction was taking place and what I could do to increase the power and force of the reaction, then I would have a better chance at creating the rocket. I am a visual learner; therefore, I started by looking for videos that examined the reaction. A video from MythBusters, a television show with trained professionals based around the idea of exploring the science around popular phenomenon, was one of the most useful resources because the video offers a simple and precise explanation for the reaction, the porous surface of the mentos coating. This idea was beneficial in choosing the materials to do the experiment. A second source that I used, a forum used to post easy experiments that make chemistry more interesting, pointed out that diet soda actually works better in the reaction to create a larger explosion. When planning to create the actual rocket, I came across a step-by-step video for people interested in making a homemade rocket (note: not a mentos and diet coke rocket). Though I did not apply much of what the tutorial showed to my rocket, it did give me an idea as to how what I should expect with a chemically driven rocket. This tutorial, like others I saw that provided tips for the design, is user generated content primarily created to share information with others. I then found a step-by-step guide to creating a diet coke mentos rocket on the eHow, a user generated content instructional guide site, Hobbies and Science instructional guide section. As opposed to a video tutorial, I found having the process verbally laid out with a list of materials very effective in preparation for the experiment. The only issue I found with this set of directions was the specific instruction to crush each candy prior to placing them into the diet coke, which I explain further in the design section. Interestingly, this site uses monetary compensation for the popularity of the guide. It brings into question the reliability of the instructions and his/her motivation in posting an instructional.
The next step was to design and test out my idea of how to get the rocket to fly. I was not interested in replicating the exact methods that I had seen in my research. While researching, I made notes regarding what method I thought would work better than others and essentially designed my own method. The materials I purchased, which actually changed later in the process, included two long metal screws, a strong magnet, two diet coke bottles and two full regular mentos candy packs. My plan was to: place as many individual mentos onto a screw (note: this link directs you to the video that gave me the idea to use the screw), tip the bottle sideways, hold the screw full of mentos in place on the side of the bottle, place the bottle against a vertical wall, release magnet and shake the bottle to create a large enough explosion for the bottle to launch off the wall. There were some problems with this plan. The screw actually damaged the surface area of the mentos, which, according to MythBusters, is the key to the nucleation (see the link to MythBusters) process that causes the reaction. The magnate was not strong enough to move the screw down the side of the plastic bottle. Finally, and most importantly, the reaction and force was not big enough for the bottle to launch.
I was able to solve my problem by using the tips I found in the planning phase of the experiment. I had to go back to the basics: create enough force to launch the bottle through the reaction. From this, I figured that I needed to increase the amount of surface area of the mentos candy touching the diet coke, which meant I needed a way to not destroy or crush the candy before placing it in the bottle. In a last effort, I pulled a bobby pin from my hair, straightened it out and used it to connect the mentos. My next step included changing the vertical platform to a horizontal one, the floor, and omitting the magnet completely from the process. This turned out to be the easier of the two methods and it worked beautifully. Although I left covered in mass amount of diet coke, I found it very fulfilling to create and modify an experiment successfully.
Through this process, I was able to identify my strengths and weaknesses when working with something new. I found that I work better when I am able to use trial and error techniques. Moreover, this experience shows me that it is important to have a knowledge base on the topic prior to attempting a new task.