I'm spending part of my summer sitting in on organic chemistry classes. Yesterday I started the second half of Organic Chem (Chem 3020). So far it's pretty great. We started in on spectrometry. Which I have been incorrectly calli
I'm particularly excited to be learning about spectrometry because of my own spectrometer that I built. It is an Ultraviolet spectrometer, made out of a basic webcam and a modified VHS box. When we first talked about this in gen chem, I started reading about them on the internet. When I found open source software, I knew I had to make one. Then I found that the same website also had assembly instructions, I was elated. I found the instructions and open source software here:
http://spectralworkbench.org/
One of the hardest parts in the assembly was taking the infrared filter out of the webcam. I accidentally broke one webcam attempting to do this. Then after I finally managed to locate and remove it, I finished putting it together and. . . nothing. I could not actually see any spectra with it. But with the help of the friendly community at spectralworkbench, I finally tweaked the angles on the camera and the DVD filter to the point where I can observe emission spectra now. I was a little disappointed to be told in class that an UV spectrometer is not very useful practically, especially compared to other types of spectrometers, but I am still excited to use it.
Also, I recently saw this great little .gif on imgur:
ng spectroscopy all this time. Nope. It is a spectrometer, meter meaning measure, since we are measuring spectra. . . anyway, we primarily covered mass spectroscopy, which was really interesting. We had talked very briefly about it in gen chem, but went somewhat more in depth today. One bit I found particularly enthralling was when he was teaching us about which bits of a hydrocarbon tear apart when the electrons are bombarding the molecule. Which bonds break, where, and when? I'm particularly excited to be learning about spectrometry because of my own spectrometer that I built. It is an Ultraviolet spectrometer, made out of a basic webcam and a modified VHS box. When we first talked about this in gen chem, I started reading about them on the internet. When I found open source software, I knew I had to make one. Then I found that the same website also had assembly instructions, I was elated. I found the instructions and open source software here:
http://spectralworkbench.org/
One of the hardest parts in the assembly was taking the infrared filter out of the webcam. I accidentally broke one webcam attempting to do this. Then after I finally managed to locate and remove it, I finished putting it together and. . . nothing. I could not actually see any spectra with it. But with the help of the friendly community at spectralworkbench, I finally tweaked the angles on the camera and the DVD filter to the point where I can observe emission spectra now. I was a little disappointed to be told in class that an UV spectrometer is not very useful practically, especially compared to other types of spectrometers, but I am still excited to use it.
Also, I recently saw this great little .gif on imgur:
I asked one of my favorite professors if we could do this reaction in lab just for fun one day this summer (because GLITTER), and he said sure, but that the reaction looked a bit funny - usually you would see more of a cloudy precipitate (like the solid yellow you see at first), not that cool crystal/glitter substance you see settling out of the solution. I then, of course, had to figure out what was going on. He set me on the right path, mentioning that a more glittery precipitate is often the result of a colder/slower reaction. After much reading, I found a likely explanation: slow reprecipitation. They added really hot water to their solutions after mixing them so that they formed PbI2(s), which redissolved due to the heat when the water was added (as temperature increases, solubility increases), then slowly reprecipitated out as crystals as the solution cooled. So cool!