Intro:
In this experiment, we built and tested composite rocket fuel and learned about the science behind how the fuel works. For the rocket fuel to work there needs to be a chemical reaction. A chemical reaction is a process where one or more substances change into a new substance. During this experiment, we learned more about chemical reactions, and were even introduced to stoichiometry. This is how my experiment went. Looking Back: My experiment didn't turn out as well as it could've. When I was putting the fuel mixture in, the paper bent and had a crease in it which made it harder to stick the football sized tin foil in. Also I don't believe the canal I drilled in the fuel was big enough. That part was important because it creates surface area needed for the fuel which I believe Brian said. The reason why mine didn't work well was because the cap came off so it didn’t even have enough thrust to push out of the test tube. Looking Beyond: When making the fuel, we used potassium nitrate and sucrose. When put together, they form a reaction that is needed for the fuel to work. The potassium nitrate gave off oxygen molecules needed for the experiment while the oxidizer and the sucrose gave off carbon, hydrogen, and more oxygen molecules that were necessary for the experiment. Besides learning about chemical reactions, we also learned about chemical equations, endo/exothermic reactions, stoichiometry, and more. First off endothermic and exothermic reactions. Endothermic reactions are reactions that pull heat in, while exothermic reactions are the opposite, they give off heat. For example combustion reactions are almost always exothermic because they give off heat. Next off chemical equations. Chemical equations help you figure out everything you need to know for each reaction. An example of a chemical equation is NaCl + KBr --> KCl + NaBr. In this equation, sodium chloride is reacting with potassium bromide to make potassium chloride and sodium bromide. For the fuel, we used the chemical equation 5C12 H22011 (sugar) + 48KNO3 (potassium nitrate) --> 24K2CO3 + 36CO2 + 55H2O + 24N2. We were also introduced to stoichiometry. It was very confusing, and involved lots of numbers but I think I understand it a little. Hopefully when we do an exclusive lesson on it I’ll get the hang of it. We used stoicheometry to figure out the percentage of potassium nitrate needed to go into the fuel for a chemical reaction. We figured out that for the reaction to work, we needed 26% of the mixture to be sugar, and 74% to be potassium nitrate. Looking Inward: I didn't get desirable results because my fuel didn't thrust up into the sky. After the cap fell off, there wasn't enough chamber pressure for the rocket to get off the ground. I believe if I had secured the rocket fuel, the launch would've been more successful, but I believe I performed well. I did my best to follow the instructions and in the end, you can't always get the results you want. Looking Forward: If I could redo this, I would do each step of the building process carefully and make sure that the rocket fuel was secure. I don't see a way I could continue this project except for if I decide to build a rocket but I'm looking towards doing lighter experiments instead. Take Away: My thoughts on this experiment were mainly that it was really cool. I especially enjoyed the part where we launched the rocket fuel. Some of the fuel went higher than I expected! During the reporting part of the experiment, I had a hard time taking notes. This was because it was difficult for me to transition between taking notes and listening to what Andrew was explaining so I had to search up a few things. But maybe next time I'll employ a new method where I listen first then write down notes after so I can comprehend what Andrew is teaching and have notes to reflect upon rather than just relying on my notes. Intro: During this project we were able to make our own battery. We used copper, zinc, and a piece of cardboard soaked in vinegar. We then stacked these materials. Each cell that we would stack added onto to the overall charge of the battery. When in contact with the electrolyte solution, Each metal forms positive ions. However zinc loses electrons more easily causing them to travel to the copper ions. Therefore the electrons transfer from the zinc to the copper. Looking Back: Our experiment worked out very well. We were able to construct a functional battery that even powered an LED light. We first sanded one side of a penny to expose the zinc and left the other side of the penny alone because we needed it to have copper. We then put the copper side down and the zinc side up and soaked cardboard in vinegar and placed it on top of the copper and repeated the stacking process seven more times. Then we tested the battery by trying to light up an LED light and it worked! This is because electrons flow from the zinc through the soaked cardboard to the copper.The reason why we repeatedly stacked the materials was so that the overall charge of the battery could increase which strengthens the battery. Looking Beyond: To make the battery there needs to be zinc, copper, and a source of electrolytes. This is because when an atom that can lose electrons easier than an atom from a different element make contact, the electrons transfer. Just like how in the experiment, when in contact with the electrolyte solution, (vinegar), the zinc loses its electrons easier so they transfer to the copperions. This illustrates the concept of oxidation and reduction. Oxidation is the loss of electrons while reduction is the gaining of electrons. In this case, the zinc goes through oxidation while the copper goes through reduction. Looking Inward: I believe what contributed to my group's desirable results was the teamwork and understanding we had. We all knew what to do and how to communicate and it all ended with us successfully making a battery and powering an LED light. I believe I did well in this project and contributed to the success in the group. Looking Forward: If I were to do this project again, I would probably have just sanded the penny patiently because when we went outside to try to sand the pennies, it was slow and not as effective as when we came back and sanded the pennies for a couple minutes. Other than that I wouldn't change anything. I would probably choose the same group again if possible because everyone was on task and productive. I don't see anyway to continue the experiment and would like to move on to exciting new ones. Take Away: This experiment taught me more about utilizing metals. I never new you could make a battery our of pennies and cardboard! It was interesting to make a functioning battery without any plugs or wires. I also didn't know that under a pennies shiny coating was a metallic like substance, I always thought that pennies were just pure copper. I enjoyed this experiment and may even use this to my own advantage! Intro:
You have probably heard of the expression, 100 pennies make a dollar. But who would want a dull penny? During this experiment, I explored how to use simple household items to turn twenty dull pennies into shiny pennies again. In this experiment I mixed vinegar and salt and used it to cleanse dull pennies. Then I rinsed half of them and didn't rinse the other half and let them dry. Observing these pennies taught me more about oxidation and how acids can dissolve the rust on pennies. Looking Back: My experiment turned out pretty good. I was able to clean lots of the dull pennies I had. I put 20 dull pennies in a salt and vinegar mixture. Then I took half of them out and washed them, and took the other half straight out of the mixture without washing them. After an hour I observed that the pennies I washed were shiny while the ones I didn't wash turned green. Looking Beyond: The pennies were dull because overtime the copper atoms combined with the oxygen atoms in the air creating copper oxide on the penny's surface. When you put the dull pennies in the salt and vinegar, the copper oxide dissolves. Also, when you put the screws in the mixture afterwards the copper coating from the pennies coats the screws making a metallic layer. The screws bubble while in the mixture because in the salt and vinegar, there's lots of hydrogen atoms missing an electron floating around called hydrogen ions. Some of the ions join together at the screw's surface and make hydrogen gas which is what the bubbles are made of. After the pennies that weren't rinsed dry, they turn greenish blue. This is because when the salt and vinegar dissolve the copper oxide layer, the copper atoms join oxygen from the air and the salt's chlorine to make a blue-green compound known as malachite. Looking Inward: I got pretty good results from this experiment. This is because I followed the steps carefully and made sure to use the right ingredients because the first time, I tried to complete the experiment with Balsamic vinegar but it wasn't as effective so I went and bought clear vinegar and the results were better. I believe I performed well in this activity. Looking Forward: I would probably have just bought clear vinegar in the beginning instead of using whatever I had in the house but other than that I wouldn't change anything. I don't believe there's a way to continue this experiment, nor would I want to continue it. I'd rather move on to a new experiment. Take Away: This experiment taught me more about how pennies rust and how to turn them back to normal again. It also taught me to kind of slow down and look at each step carefully before I rush and do things because I made lots of mistakes and had to keep re-doing the experiment many times until I finally did it correctly and got desirable results. Intro:
You may notice that when you leave a bitten apple or apple slice outside for a while, the white inside starts to turn brown. In this experiment I explored more about why apples turn brown, and how acid can be used to preserve them. I found that acids can be used to preserve the white part of an apple. You can apply these acids to the white part of the apple to help keep it fresh longer. For example in this experiment you can use lemon juice, limes, cranberry juice, and more because they have acids in them. However I've only used lemon juice on the apple. Maybe in the future I can use a different acid if I want to continue this experiment. Looking Back: My experiment was a success. It worked out really well because the steps were easy and simple. I just cut an apple in half and applied lemon juice to one of the sides and left the other half bare. Then I let the slices sit out for a while and when I compared them, the slice with lemon juice stayed fresh and glistened while the bare slice was browner and dry. Looking Beyond: When an apple is cut open, it releases an enzyme called polyphenol oxidase which reacts with the oxygen in the air. This causes the apple to turn brown. When lemon juice is applied to the apple slice, the ascorbic acid from the lemon juice reacts with the air instead of the polyphenol oxidase therefore preserving the apple's freshness. Looking Inward: I believe what contributed to my success with this experiment was the simplicity of the steps. How can you mess up cutting an apple in half, adding lemon juice to one of the slices, and just watching what happens? I believe I performed well during this experiment and followed all of the steps and precautions for the activity. Looking Forward: I wouldn't change anything if I were to do this again because I did everything that I could to make this experiment a success. I could continue this project by coating apple slices with other juices containing ascorbic acid but I would rather move on to other experiments. Take Away: This experiment taught me more about why apples turn brown and how I can preserve them. It always has annoyed me that I couldn't preserve apples after I cut them up and that I always have to finish them, but now I know how to preserve them and can't wait to use this experience in my everyday life. |
BettyMy name is Betty and this is my chemistry blog where I'll perform all sorts of cool science experiments. Enjoy! Archives
May 2015
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