TmNhRhMgBrSe - 14-4-2020 at 05:57
I dissolve MnCO3 in ethanoic acid and then add sodium thiocyanate. Solution become orange. Is manganese thiocyanate orange?
Bedlasky - 14-4-2020 at 05:58
No, it's iron contamination.
TmNhRhMgBrSe - 14-4-2020 at 10:01
I mix MnO2, oxalic acid and sulphuric acid to make MnSO4 solution. Solution is orange yellow. I use Nurdrage way to remove iron. MnSO4 solution become
pink. I add sodium carbonate to make MnCO3. Precipitate is pink. I want to make Mn(NO3)2. If the MnCO3 still have iron then how to remove remaining
iron?
Bedlasky - 14-4-2020 at 13:35
I have MnSO4 and MnCl2. MnSO4 should contain Fe impurities because I made it from battery acid, H2O2 and MnO2. And battery acid contain lots of iron.
And about purity of MnCl2 I am not sure. I always think that this colour is caused by Fe-NCS complexes. But maybe I am wrong.
Remy mentioned green Mn(NCS)2.4H2O which forms green concentrated solution and pink dilute solution. Anhydrous Mn(NCS)2 is yellow.
[Edited on 14-4-2020 by Bedlasky]
UC235 - 14-4-2020 at 13:38
Are you sure you're not getting decomposition due to low pH? Guanidine thiocyanate turns fluorescent yellow if you hit it with bleach. Im not sure
what the involved species are, though. Also, the color change due to iron is very sensitive. It could be a combination of problems. Perhaps you are
seeing an oxidized Mn-SCN complex that mimics Fe(III)?
That being said, is Mn(SCN)2 even something you can readily isolate? What is the goal here?
TmNhRhMgBrSe - 15-4-2020 at 05:06
I want to remove iron in MnCO3 before make manganese nitrate.
[Edited on 20年04月15日 by CELamCheng]
TmNhRhMgBrSe - 16-4-2020 at 01:52
How to remove iron in MnCO3 before make manganese nitrate?