For this project, our goal was to take one of our older projects and do it again, but in a different and better fashion. Of the projects I had done over the year, I felt that the Hybrid Car Project (click here to see more about the first project) was one that I could have spent more time on to improve and recreate, and along with three other classmates who wanted to redo that project, we decided to make an explosive car. The project involved principles of physics, such as thrust, momentum, and velocity, but we also wanted to incorporate elements of chemistry to make our project truly novel. The general feature of our car was that it would be driven by a small explosion, involving a lighter and a balloon filled with hydrogen and oxygen gas.
The first method we employed to generate the hydrogen gas was through the process of electrolysis, as shown to the right. By running a current through a container of a saturated saltwater solution, the water molecules would split into hydrogen and oxygen ions. At the negative terminal of the system, positive hydrogen ions would accumulate, and the negatively charged oxygen ions aggregated at the positive terminal. Initially, the plan was to use this to generate large amounts of gas that would enter a tube, which we would then seal. Upon "starting" the car, we would remove the seal on the end of the tube facing away from the car and quickly light it, creating an explosion that would propel the car forward. However, the electrolysis method was unable to produce a sufficient amount of gas, and as a result, we had to find another option to produce a significant amount of hydrogen that we could contain.
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After some careful deliberation, we decided to use a single displacement chemical reaction to produce the hydrogen. Our final reaction that we decided upon was a reaction between hydrochloric acid and zinc. In the reaction, the zinc cations would replace the hydrogen atoms bonded to the chloride ions to form zinc chloride and hydrogen gas, which would then be gathered in a balloon. A video demonstrating how we accomplished this can be seen below on the left. After the hydrogen gas and some oxygen gas entered the balloon, we tied it off and placed it inside a large tube of PVC pipe. Once the whole system was ready, we took the tube, balloon, and a barrier (safety first, everyone) to the parking lot behind our class to test it out. You can watch the combustion below, in the video on the right.
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Our presentation, including the results of the experiment and an image of the interior of the PVC tube can be seen in the file to the right.
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Key Concepts:
Electrolysis- Chemical decomposition as a result of an electric current passing through a solution, such as saltwater.
Ion- An atom or molecule with an electric charge.
Cation- A positively charged ion, such as hydrogen.
Anion- A negatively charged ion, like oxygen or a chloride ion.
Single Displacement Reaction- A reaction in which one cation switches position with another cation in a compound. For example, hydrogen and zinc swap positions when hydrochloric acid (hydrogen and chloride) and zinc react to form zinc chloride and hydrogen gas.
Combustion- The reaction of a substance, which in this case was hydrogen, and oxygen that produces heat and water in the form of water vapor or liquid.
Reflection:
I think I enjoyed this project more than any of the other ones this year because I was working with great group members and the topic which we were dealing with was so open-ended that we could really use our creativity and imagination. In the end, even though we didn't have enough time to equip our explosive balloon apparatus to a car, our experiments were still successful. In some of our tests, with the proper combination of hydrogen and oxygen, we were able to produce enough thrust to push the PVC tube. With some more time, and a better understanding of the chemistry and physics behind explosions, we could have adapted our process to finally move a car. Nonetheless, this project had its fair share of peaks and pits. The first peak was how well my group members and I were able to work together, and the fact that we were able to do work and enjoy what we were doing at the same time. Rather than being worried or stressed, I found myself laughing and joking most of the time, with a fair share of staying focused and determined. One pit was our time management, however. Looking back on it, we spent too much time trying to utilize electrolysis to generate the hydrogen, and by the time we realized that the zinc reaction would be much more efficient in making hydrogen gas, there was less than a week left. On that note, our second peak was how quickly we were able to adapt to the situation, and how well we were able to find an alternative method of hydrogen production after our first plan did not work properly. Our second pit was, as a whole, personal safety. With a name like "Hydrogen Explosion Powered Car," it is safe to assume that we were putting ourselves in harm's way for the sake of science. First, with our chemical reaction, the fact that we were using a balloon meant that it could pop, and pop it did. Always remember to keep your goggles on your eyes and not on your forehead. Otherwise, the eyewash is not a particularly pleasant experience. Second, when igniting an explosive balloon, make sure you have some sort of barrier between you and the tube. Also make sure to move your hand away from the tube's opening quickly after lighting the balloon, because flames travel quickly. And burn. That part is self-explanatory. Otherwise, this project was amazing, and I learned a lot from it, especially given the fact that we haven't taken chemistry yet.
Electrolysis- Chemical decomposition as a result of an electric current passing through a solution, such as saltwater.
Ion- An atom or molecule with an electric charge.
Cation- A positively charged ion, such as hydrogen.
Anion- A negatively charged ion, like oxygen or a chloride ion.
Single Displacement Reaction- A reaction in which one cation switches position with another cation in a compound. For example, hydrogen and zinc swap positions when hydrochloric acid (hydrogen and chloride) and zinc react to form zinc chloride and hydrogen gas.
Combustion- The reaction of a substance, which in this case was hydrogen, and oxygen that produces heat and water in the form of water vapor or liquid.
Reflection:
I think I enjoyed this project more than any of the other ones this year because I was working with great group members and the topic which we were dealing with was so open-ended that we could really use our creativity and imagination. In the end, even though we didn't have enough time to equip our explosive balloon apparatus to a car, our experiments were still successful. In some of our tests, with the proper combination of hydrogen and oxygen, we were able to produce enough thrust to push the PVC tube. With some more time, and a better understanding of the chemistry and physics behind explosions, we could have adapted our process to finally move a car. Nonetheless, this project had its fair share of peaks and pits. The first peak was how well my group members and I were able to work together, and the fact that we were able to do work and enjoy what we were doing at the same time. Rather than being worried or stressed, I found myself laughing and joking most of the time, with a fair share of staying focused and determined. One pit was our time management, however. Looking back on it, we spent too much time trying to utilize electrolysis to generate the hydrogen, and by the time we realized that the zinc reaction would be much more efficient in making hydrogen gas, there was less than a week left. On that note, our second peak was how quickly we were able to adapt to the situation, and how well we were able to find an alternative method of hydrogen production after our first plan did not work properly. Our second pit was, as a whole, personal safety. With a name like "Hydrogen Explosion Powered Car," it is safe to assume that we were putting ourselves in harm's way for the sake of science. First, with our chemical reaction, the fact that we were using a balloon meant that it could pop, and pop it did. Always remember to keep your goggles on your eyes and not on your forehead. Otherwise, the eyewash is not a particularly pleasant experience. Second, when igniting an explosive balloon, make sure you have some sort of barrier between you and the tube. Also make sure to move your hand away from the tube's opening quickly after lighting the balloon, because flames travel quickly. And burn. That part is self-explanatory. Otherwise, this project was amazing, and I learned a lot from it, especially given the fact that we haven't taken chemistry yet.