Chemical Dominoes Project
What we did:
This project was similar to what we did two years ago with the Rube Goldberg machine, but instead of physics concepts powering our machine, we used what we learned about chemistry. In brief, we used a self-lighting combustion reaction to light our bunsen burner to create carbon dioxide gas (by way of calcium carbonate), which would raise a lever, spilling copper chloride into a dish, deteriorating an aluminum strip, triggering our LED circuit.
The Chemistry Behind It:
Combustion reaction: 14KMnO4 + 4C3H5(OH)3 -> 7K2CO3 + 7Mn2O3 +5CO2 +16H2O
The first step in our machine was to light our bunsen burner. Right off, our group decided that matches were too pedestrian, so we threw together a self-lighting mixture of Potassium Promanganate and Glycerin. When combined, these two compounds react violently, producing a bright purple flame and a lot of smoke. Ms. Vogl was reluctant to let us do this indoors.
Decomposition Reaction: CaCO3 -> CO2 + CaO
After the combustion reaction lit our bunsen burner (by way of a fuse), it heated a flask of Calcium Carbonate. While this leaves no visible change, the reaction produces an amount of Carbon Dioxide gas, which we captured in a balloon and used to raise a lever (meter stick with some weights on it), causing a copper chloride solution to fall into a dish.
Single Replacement Reaction: Al(s) + CuCl2(aq) -> Cu(s) + AlCl3 (aq)
As the last step in our haphazard device, we set a decomposition reaction to light an LED circuit, with a strip of alluminum bridging one of the wires. As the alluminum deteriorates, so does it's conductivity. This redirects power to a parallel circuit, lighting our LED. The End.
Reflection:
I enjoyed this project, mostly because we had free reign over what we were allowed to build and we had a very good group. Everyone contributed to the final project, which worked (almost) flawlessly. In the beginning, we experienced difficulty with the combustion reaction and the lighting of the bunsen burner. We quickly concluded that lighting gunpowder fuses with explosions and using them to light flammable gas was a bad idea, so we lit string soaked in alcohol with the explosions instead. It worked perfectly. As for the rest of the device, we never really encountered problems with it, The remaining steps were straightforward and reliable, and we never had any real issues with them. In conclusion, I couldn't have asked for a better project, except for the fact that our machine was rather anticlimactic. All of this fire and acid, only to light a small LED.
This project was similar to what we did two years ago with the Rube Goldberg machine, but instead of physics concepts powering our machine, we used what we learned about chemistry. In brief, we used a self-lighting combustion reaction to light our bunsen burner to create carbon dioxide gas (by way of calcium carbonate), which would raise a lever, spilling copper chloride into a dish, deteriorating an aluminum strip, triggering our LED circuit.
The Chemistry Behind It:
Combustion reaction: 14KMnO4 + 4C3H5(OH)3 -> 7K2CO3 + 7Mn2O3 +5CO2 +16H2O
The first step in our machine was to light our bunsen burner. Right off, our group decided that matches were too pedestrian, so we threw together a self-lighting mixture of Potassium Promanganate and Glycerin. When combined, these two compounds react violently, producing a bright purple flame and a lot of smoke. Ms. Vogl was reluctant to let us do this indoors.
Decomposition Reaction: CaCO3 -> CO2 + CaO
After the combustion reaction lit our bunsen burner (by way of a fuse), it heated a flask of Calcium Carbonate. While this leaves no visible change, the reaction produces an amount of Carbon Dioxide gas, which we captured in a balloon and used to raise a lever (meter stick with some weights on it), causing a copper chloride solution to fall into a dish.
Single Replacement Reaction: Al(s) + CuCl2(aq) -> Cu(s) + AlCl3 (aq)
As the last step in our haphazard device, we set a decomposition reaction to light an LED circuit, with a strip of alluminum bridging one of the wires. As the alluminum deteriorates, so does it's conductivity. This redirects power to a parallel circuit, lighting our LED. The End.
Reflection:
I enjoyed this project, mostly because we had free reign over what we were allowed to build and we had a very good group. Everyone contributed to the final project, which worked (almost) flawlessly. In the beginning, we experienced difficulty with the combustion reaction and the lighting of the bunsen burner. We quickly concluded that lighting gunpowder fuses with explosions and using them to light flammable gas was a bad idea, so we lit string soaked in alcohol with the explosions instead. It worked perfectly. As for the rest of the device, we never really encountered problems with it, The remaining steps were straightforward and reliable, and we never had any real issues with them. In conclusion, I couldn't have asked for a better project, except for the fact that our machine was rather anticlimactic. All of this fire and acid, only to light a small LED.