Scrap Science - 2020-11-18
We do our best to follow a 100 year old paper describing the synthesis of permanganate from manganese metal. DOI of the paper: 10.1021/ie50141a012 Link to the video where we make manganese metal: https://youtu.be/wBWba_anewQ The setup is very simple, using a separated electrolytic cell (with a clay pot diaphragm) and a 25% potassium carbonate electrolyte, we use a manganese anode to make permanganate at a high efficiency. In doing this, we were able to make approximately 1.5g of potassium permanganate as a 0.21M solution. Sadly, we don't manage to crystallise any pure permanganate from solution. This electrolytic method offers some serious advantages over most other permanganate syntheses in that it offers a high efficiency and is capable of generating a highly concentrated solution (possibly getting close to saturation). It also doesn't require aggressive oxidisers or high temperatures. The only major downfall of this pathway is the fact that it uses manganese (or ferromanganese) metal as a starting material, which is a little difficult to get hold of. In the future, I'll definitely be revisiting this by attempting to make a manganese electrode from manganese sulfate (a much more available compound) and using that as the manganese source for the electrolysis stage. This video is basically just a proof of concept for the process, so I haven't attempted to calculate the yield or efficiency of the reaction. Again, this is definitely something I'll revisit in the future with a bit more of a controlled setup, so stay tuned!