Manganese compound?

Few days ago,I was grinding a mixture of potassium permanganate and glucose in granite mortar.Then I use the mixture and left the mortar for a day.The colour of the residue is dark brown,before I left it it was a bit whiter because of glucose.

My theory is some of the glucose had reduce the potassium permanganate to Manganese dioxide.Then I took the mortar to the sink and wash it with water.The water turn deep violet indicating potassium permanganate is still there,but leaving a dark area........guess it is manganese dioxide.Ok,in order trying to get rid of that stain,I pour in bleach (sodium hypochlorite).

After the next day,I pour the bleach that I left in my granite mortar and I receive this odd coloured solution(pictured),Is this a compound of manganese or just solution of potassium permanganate?

(I'm sure that I wash the mortar untill all the potassium permanganate dissolved)

Quote: Originally posted by Ozone

You are lucky that mixture did not catch fire or worse when you were grinding it. Carbohydrate- permanganate mixtures are notorious. I have set mixtures of table sugar (sucrose) and permanganate off by tapping with a hammer. Apparently a flash mixture can also be so made. [Edited on 19-8-2010 by Ozone]

I do concern about that risk Ozone,that mix sparks a few time when I grind it.

I try to precipitate manganese carbonate with sodium carbonate solution.And I get this result(pictured).I gues the brown precipitate is manganese carbonate.the solution stay pink,so maybe Bezaleel theory is right,it was contaiminated with KMnO4.Therefore,this thing come from my mortar washing's water.





12AX7,thanks for your tips.I'll try that later.......but the sad thing is,I have no hydrogen peroxide with me now......I have see a video about making manganese sulfate.but,manganese chloride can be made by similar way I gues,here the link:

http://www.youtube.com/watch?v=2gXByJkg0iY

Got to try it,seem interesting to me.

[Edited on 19-8-2010 by kuro96inlaila]

Quote: Originally posted by Ozone

You are lucky that mixture did not catch fire or worse when you were grinding it. Carbohydrate- permanganate mixtures are notorious. I have set mixtures of table sugar (sucrose) and permanganate off by tapping with a hammer. Apparently a flash mixture can also be so made. The dark brown was MnO2. Although I have generated MnO4 from MnCl2 via bleach (NaOCl), which was verified by UV-Vis spectroscopy, your mix looks like MnCl2 with maybe a*trace* of MnO4 (provided that the color saturation of the photo is good). It might be of interest to add further NaOCl and see what happens. What was your stoichiometry? Cheers, O3

As the conclusion,the pink colour was manganate ion,not being manganese chloride..........I plan to do experiment using bleach and lab reagent grade manganese dioxide and I'll report the result later.

Ok,here is the result:

I pour 15ml of bleach into testube and put about 8g of manganese dioxide into it.I also prepare similar mixture but in bigger amount in 250ml beaker.The mixture bubbled but I cannot identify what gas it is:



As I swirl the testube,the reaction become faster,but it come back bubbling smoothly not long after i stop swirling the testube.Then I let it sit until the evening of that day.

At the evening:The reaction is still proceeding.but the solution is pink(damn camera,you take it purple).



Then I leave the reaction going without disturbing it,until the completion.I dont know the exact time when the reaction actually come to the end.I come to it after about two days later(Forgot about the experiment though).I got these result:




Ok,that is actually faint pink.Maybe manganese chloride have been form.Meanwhile at the beaker:




HARGH!!!WHAT IS THIS THING!!!The solution was intensely purple like permanganate ions.Does permanganate can be form from this.Wikipedia say that sodium permanganate can be prepared by the reaction of manganese dioxide with sodium hypochlorite:

2 MnO2 + 3 NaClO + 2 NaOH → 2 NaMnO4 + 3 NaCl + H2O

I think cations and anions ions test should be made to figure what compound is this........What do you think of this (the whole experiment) my fellow friends?