quest - 22-4-2004 at 06:16
I know KMnO4 and sulfur are sensitive together.
Why is that?
What is the catalytic decomposition of the mix?
And what is the mechanics of the reaction?
thanks,
quest
vulture - 22-4-2004 at 07:50
Sulfur always produces traces of acid.
KMnO4 is highly unstable in acidic environment. Also, the decomposition of KMnO4 is autocatalyzed by Mn2+ which is formed in acidic environment.
t_Pyro - 22-4-2004 at 19:04
I've heard that explanation lots of times now, and probably it is the right one, but I'm still kind of unconvinced.
If the unstability is due to the "acidic environment" produced by sulfur, shouldn't the mixture be perfectly stable in an anhydrous
atmosphere? Without water, there's no chance whatsoever of any oxyacid of sulfur forming. Sulfur osxides might form, but without the presence of
any H<sup>+</sup> ions, it should not make any difference!
Further, which compounds of sulfur are formed under normal circumstances to provide an "acidic environment"?
vulture - 23-4-2004 at 05:42
Sulfurous acid, which get oxidized by the KMnO4 to sulfuric acid.
Furthermore, most technical sources of sulfur are always somewhat acidic.
Under perfect anhydrous conditions it's more stable, yes. But who's able to test his stuff under perfectly anhydrous conditions?