renoes
Harmless
Posts: 2
Registered: 16-1-2006
Location: Helsinki
Member Is Offline
Mood: hyvää (fine)
|
|
Oxidation of Mn2+ to MnO2
Hei,
I have found in this forum a discussion about Subject: Strenght of oxidizers.
There were several inorganic chemists I guess discussing also about kinetics and not only about the strengths of oxidisers.
I want to oxidise Mn2+ to MnO2, I have done it with KMnO4 and with CLO3-, both of them working fine, giving different types of MnO2.
I was wondering if someone of you might know about a more powerful oxidiser(faster kinetics) then CLO3- for this reaction (MnCO3 In nearly conc HNO3)
S2O8_2- does not really work well (with heating maybe)
today I have read about BiO3- (or does it shoot over (MnO4-), also if the amount of BIO3- is smaller or the pH higher?)
what about IO3- and Cr2O7-
actually it would be best if there would be no residue in the MnO2.
Any idea?
|
|
|
12AX7
Post Harlot
Posts: 4803
Registered: 8-3-2005
Location: oscillating
Member Is Offline
Mood: informative
|
|
Can't just bubble dilute O2 (i.e. air) through it?
Oxygen is right next to fluorine on the periodic table, pretty nice oxidizer.
I haven't checked a redox table but I suspect chromate may not be able to do it. Well, maybe MnO2, but nothing higher for sure. Well heck- I can
make chromate by chlorinating a chrome salt, but MnO2 (at least in acid) is strong enough to oxidize chlorine. That means chromate must be below
MnO2, again depending on pH.
But yeah, go search for a potential chart and look up the voltages for the reactions you're looking at. If one has more voltage than Mn(2+) >
Mn(4+), then it can proceed.
BTW, S2O8(2-) you probably didn't even give a chance, they say it's real slow. A silver catalyst might help?
Tim
|
|
|
mantis
Harmless
Posts: 38
Registered: 17-7-2005
Member Is Offline
Mood: No Mood
|
|
what about H2O2?
But I think using air oxi. agent would be the best and cheapest way, maybe it will need some time.
|
|
|
woelen
Super Administrator
Posts: 7977
Registered: 20-8-2005
Location: Netherlands
Member Is Offline
Mood: interested
|
|
Precipitate the material with NaOH and then add dilute H2O2. Any excess H2O2 will be decomposed quickly, hence no residues remain. The MnO2 can be
filtered from the liquid and then rinsed and dried.
|
|
|
renoes
Harmless
Posts: 2
Registered: 16-1-2006
Location: Helsinki
Member Is Offline
Mood: hyvää (fine)
|
|
thank you all for your answers
I am a little courious what kind of MnO2 I will get with your proposals.
Good that no one proposed me to use fluorine or Mn2O7:-)
Sönke
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
