feacetech - 18-10-2007 at 16:28
Some KMnO4 that I ordered just turned up, it is ajax fine chem UNIVAR(analytical reagent).
Now the KMnO4 is green in colour on the outside of the crystalls and had a large clump in the container when i opened it.
It goes puple in water like it should, when ground alittle it truns purple.
now is the quality a issue? It seems to me that the outside of the crystalls have degraded.
what do you guys think?
it looks very much different to some old stock i have which is purple with a metallic luster, the stuff from ajax has that descripton on the bottle
but fails to comply in the bottle.
[Edited on 19-10-2007 by feacetech]
Xenoid - 18-10-2007 at 18:10
KMnO4 is commonly described as dark purple crystals, almost black, with a greenish lustre.
"UNIVAR", quite expensive, eh! Is this actually destined for analytical purposes or was it the only grade you could obtain!
Regards, Xenoid
woelen - 18-10-2007 at 22:12
The green color is not a problem. The light, reflecting from the crystals may have colors ranging from very dark green to very dark purple, almost
black. This effect is particularly strong for larger crystals of potassium permanganate.
feacetech - 18-10-2007 at 23:56
The crystalls are quite small. It is sort of a green dark grey, just so different from my other lot of KMnO4 which is large purple crystalls.
So shes all good.
As for its use some of it is for analysis (nitrite free water) and some for play.
It wasnt too expensive but hey im not paying. 
Fleaker - 19-10-2007 at 16:11
Univar products are actually really cheap if you buy in bulk, as in $3/L for 15L of nitric acid, cheap. My lab grade KMnO4 has a greenish tinge, and
Baker's supposed to be ''the best''.