[BROe]

Today I conducted an experiment in an attempt to produce MnCl₂ by the following reactions. Stoichiometric amounts were used, I designed my reaction to produce about 10g of MnCl₂.

KMnO₄ + HCl  2KCl + MnCl₂ + 5Cl₂

I then added Na₂CO₃ to precipitate MnCO₃ and isolate it from aqueous Potassium with the following reaction.

2KCl +  MnCl₂ + 2Na₂CO₃  K₂CO₃ + MnCO₃ + 4NaCl

I then expected to filter the MnCO₃, dispose of the other soluble chemicals, and then run more HCl through the filter to re-dissolve the MnCO₃ as MnCl₂, boil down and crystallize the solution, obtaining crystalline MnCl₂.

The first step/reaction seemed to proceed fine, I added HCl to the KMnO₄ solution as incrementally as I could until I started to smell the Chlorine, at which point I moved the beaker outside and waited a safe distance away until Chlorine was no longer being produced. Then I slowly added the Sodium Carbonate, no problems there. When I filtered the solution, the insoluble substance remaining on the paper was a black or very dark purple color, and the soluble portion was a vivid purple color. It is concerning this part that I am confused as Manganese Carbonate is supposed to be a light pinkish color, is it possible that I made MnO₂ instead? As I am currently filtering the solutions a rapid response would be greatly appreciated. I would also be happy to supply any additional information for clarity's sake.

[Borek]

You need a huge excess of HCl. If the pH of the solution is not low enough, permanganate won't get reduced to Mn²⁺. Solution after the reaction should be just pale pink, any other color means it didn't go to the end.

Why do you start with a permanganate? It is about twice more expensive than MnO₂ as a source of Mn.

I would try to use some reductor - like sodium sulfite. You will still need to keep the pH low.

[BROe]

I started with permanganate because that was what I had on hand. I did some research and using sodium sulfite is definitely a safer alternative to HCl when reducing KMnO₄.
Though I don't have any sodium sulfite on hand, I do have quite a bit of stump remover which I know to be sodium metabisulfite. I plan to make the stuff by mixing the metabisulfite with HCl in a stoppered flask, and letting the SO2 it produces bubble through an NaOH solution.

Update: If I keep the amount of water in the flask containing the metabisulfite and HCl low by pouring the acid over dry Na2S2O5, will the SO2 produced evolve from the solution or react with the water to make H2SO3?