Sciencemadness Discussion Board

Cu,Mn, and ferrocyanide

bismuthate - 12-5-2014 at 16:26

Quite by accident in an attempt to test out my MnSO4 I found that upon mixing CuSO4, MnSO4, and K4[Fe(CN)6] a purple precipitate is formed. What could this be? Could it be manganese copper ferrocyanide? (sorry I don't know much about double salts, so I need some help)

HgDinis25 - 12-5-2014 at 17:01

Could you provide more details? In wich order where the reagents added, and how much of each?
If you added the CuSO4 to K4[Fe(CN)6] you should have observed a brownish-redish precipitate of Copper (II) Ferrocyanide Cu2[Fe(CN)6].

bismuthate - 12-5-2014 at 17:09

Well I added the MnSO4, then the CuSO4, then the ferrocyanide. (I also did it adding the CuSO4 last. I have not mesured them as it appears to work in all proportions. I willl soon get more info.

Metacelsus - 12-5-2014 at 18:19

Test solely manganese sulfate and the ferrocyanide.

bismuthate - 13-5-2014 at 03:18

That merely precipitates a white solid. Over time (overnight) the solid turns a light brown. I tried to see if the purple color was just from the two colored precipitates being mixed by mixing a BaSO4, CuSO4 and ferrocyanide. This just lightened the brown colour and made no purple. I still have my suspicions that it could be a physical phenomenon instead of chemical.