Chemistry
I acquired a ~16 year old laptop. The mat black plastic top (back of the LCD) is sticky. At first I thought the previous owner had stickers on the back that were removed. But that seems like a bad theory now. I rubbed it with a cloth and denatured alcohol and it only got slightly less sticky, but black residue came off on my hands and the cloth. This is apparently not adhesive.. it’s the plastic itself. What’s my best move? I don’t suppose I can do anything to re-polymerize it. I don’t care about cosmetics.. I just don’t want it to be sticky and marking anything that touches it. One temptation is to put plastic film on it, like cling wrap. But that could just make a bigger mess.
In the heart of World War II, as the Nazis took control of Copenhagen, a peculiar situation took place at the Institute of Theoretical Physics, led by physicist Niels Bohr. Two Nobel laureates Max von Laue and James Franck, fearing the confiscation of their gold Nobel Prize medals by the Nazis, had sent their medals to Bohr for safekeeping. On the day the Nazis arrived in Copenhagen, Hungarian chemist Georgy de Hevesy, who was working in Bohr's lab, devised a plan to prevent the discovery of the medals. Initially considering burying the medals, they quickly dismissed the idea, fearing the thorough searches the Nazis would conduct. Instead, de Hevesy proposed a chemical solution — literally. Utilizing a mixture known as "aqua regia" (a blend of hydrochloric and nitric acids), he set about dissolving the gold medals. This concoction is one of the few substances capable of dissolving gold, a notably unreactive element. As the Nazis marched outside, de Hevesy dissolved the precious medals, reducing them to a colorless solution that eventually turned bright orange. The liquid containing the dissolved gold was then placed on a high shelf in the laboratory, where it remained unnoticed throughout the Nazi occupation. Post World War II, upon returning to the laboratory after V-E Day, de Hevesy found the beaker undisturbed on the shelf. The gold was recovered from the solution and returned to the Nobel Prize committee, who then reminted the medals and presented them back to Laue and Franck in a ceremony in 1952. Source: Fermat’s Library via LinkedIn
Periodic Videos have updated their scandium video.
Another great video from NurdRage. One of the most detailed and methodical YouTube chemists.
New NurdRage video! Nice to see another amateur-accessible source of thorium, since incandescent gas mantles have mostly switched to yttrium. I wonder what the easiest way would be to reduce the thorium dioxide to thorium metal?
Making liquid nitrogen is quite an achievement, especially using salvaged air conditioner and refrigerator parts. A nice application of the Joule-Thomson effect and countercurrent exchange too.
Another useful example of producing a strong acid from a weak acid by using precipitation as the driving force.
Cody plays with thermite... again.
cross-posted from: https://sh.itjust.works/post/21614029 > One of the OG YouTube chemists dabbles in some radiochemistry and spectroscopy.
Not very practical, but the chemistry is interesting. Producing a strong acid from a weak acid by using precipitation as the driving force is something I don't see very often.
A bit of analytical chemistry for a change. I had never heard of a pycnometer!
Very useful video. Nitrate salts are a foundational feedstock in amateur (and professional) chemistry. Edit: NurdRage reuploaded a slightly censored version: https://www.youtube.com/watch?v=RlonW4iJYrw
NurdRage has published a couple videos on oleum synthesis: - [Lab Notes - Making Oleum - Successful - (April 21-2024)](https://www.youtube.com/watch?v=wB2zzm8VP9Y) - [Lab notes - Making Oleum - 20% yield improvement - (May 4th - 2024)](https://www.youtube.com/watch?v=hUyJ6CibhSg) Still optimizations to be done, but cool work so far. I love that one of the OG chemistry YouTubers is still doing interesting work.
A long-time viewer of Periodic Videos grew up to study chemistry, and invented a new synthetic route for thalidomide. Also, TIL that thalidomide still has several medical uses, as long as the recipients are not pregnant.
Cody Reeder makes thermite and has a nice "campfire".
The manual for my dishwasher says to refill salt just before running a wash cycle, because if any grains of salt spill onto the stainless steel interior it will corrode. If it runs right away, no issue because the salt is quickly dissolved, diluted, and flushed. So then I realized when I cook pasta I heavily salt the water (following the advice that pasta water should taste as salty as the ocean). But what happens when I leave that highly salty brine in a pot, sometimes for a couple days to reuse it? Does that risk corroding the pots?
www.compoundchem.com
If you don't want to watch the entire video, it's a [Carborane acid](https://en.wikipedia.org/wiki/Carborane_acid). I'd love to see what the molecular orbitals look like. It's not every day that you see carbon forming six "bonds".
cross-posted from: https://lemmy.dbzer0.com/post/12359577 > There are a few youtube videos where someone suggests using sulfuric acid to clean a secondary plate-style heat exchanger ([for example](https://invidious.fdn.fr/watch?v=t6PCK6_r99Q)). Yet I’ve heard sulfuric acid is extremely corrosive to metal, so something seems off about that advice. I certainly would not want an internal leak to cause radiator fluid to enter the tap water. I saw a drop of sulfuric acid land on a galvanized steel pipe once and within minutes it was rusted on the spot. > > [This guy](https://invidious.fdn.fr/watch?v=3ljHwrbQQE4) also says sulfuric acid is an option but also says there is a safer alternative acid -- yet he did not mention what it is! Does anyone know? > > [This guy](https://invidious.fdn.fr/watch?v=8-YYjiqO_v4) says he uses an ultrasonic bath but he does not say what chemicals he uses. Would distilled white vinegar be good for this? > > Note these questions are very loosely related to [this thread](https://lemmy.dbzer0.com/post/12359198) which describes a problem I am having, but really it’s a separate discussion. Secondary exchangers need periodic maintenance regardless of whether this is my current problem. I saved my previously clogged heat exchanger from a few years ago so I could work on cleaning it. I have a quite small ultrasonic I could try, but I cannot submerge the whole exchanger. I would have to stand it on end and only clean a few centimeters deep.