Recovery of Potassium Permanganate from Old Solutions
Going through all of my old solutions, there were a few I simply can’t explain. These are two that I mixed up mostly because I had the materials to do so, and having more bottles on the shelf made me feel like I had a better lab. I think I only ever used these to mix dilutions, so they never had any real purpose. I wanted to get rid of them, but I didn’t want the small amount of permanganate to go to waste. Being as contaminated as it was, though, the only thing it was good for was a little “rapid oxidation” demo!
The procedure here was pretty simple. Dump the solutions into a dish, protect the situation from as much dust as possible, and let the water evaporate for a few weeks. I was going to take some photos along the way, but I basically forgot about it! The hardest part of this whole endeavor was trying to get the poor little dish clean!
That’s about all there is to say, and I had just enough to ignite a small amount of glycerin. In fact, I was tempted not to publish this video at all because there really wasn’t much to it. As a young chemist, I enjoyed showing the decomposition of hydrogen peroxide with manganese dioxide. I would have to do the demonstration in a disposable glass jar because I had no idea how to clean the manganese stains off the glass. I don’t remember how or when I learned that dilute hydrochloric acid and dilute hydrogen peroxide mixed together dissolved them instantly. But in case another young chemist was struggling with that problem, I included this helpful tip in the video.
Sometimes, we go at a project with high hopes and it doesn’t turn out as spectacular as we had planned. In this case, I was admittedly rather disappointed in the outcome. First, the excessive contamination of the permangante (which was partially expected). Then, how little there was in that solution (which I should have expected based on concentration). And mostly the little crystallizing dish being cosmetically wrecked. But I went with it anyway, and even if it’s not my favorite video it might help someone.
Oh well. At least I have two more bottles off the shelf!
