itsallgoodjames
Hazard to Others
Posts: 276
Registered: 31-8-2020
Location: America Lite
Member Is Offline
|
|
Removal of caked on MnO2 from round bottom flask?
Is there an easy way to do this? I have been unable to wash it out with water, and I can't get a brush to reach all the inner surfaces. Thanks in
advance for the help!
Nuclear physics is neat. It's a shame it's so regulated...
Now that I think about it, that's probably a good thing. Still annoying though.
|
|
|
Antigua
Hazard to Others
Posts: 155
Registered: 27-9-2020
Member Is Offline
|
|
Almost everything works... sodium bisulfite (so sodium metabisulfite too), dilute HCl, even some detergents with chelating agents apparentely.
|
|
|
itsallgoodjames
Hazard to Others
Posts: 276
Registered: 31-8-2020
Location: America Lite
Member Is Offline
|
|
Oh, thanks. I wasn't aware it was so simple
Nuclear physics is neat. It's a shame it's so regulated...
Now that I think about it, that's probably a good thing. Still annoying though.
|
|
|
Bedlasky
International Hazard
Posts: 1241
Registered: 15-4-2019
Location: Period 5, group 6
Member Is Offline
Mood: Volatile
|
|
Oxalic acid or hydrogen peroxide are also good options.
|
|
|
itsallgoodjames
Hazard to Others
Posts: 276
Registered: 31-8-2020
Location: America Lite
Member Is Offline
|
|
Doesn't MnO2 catalyze the decomposition of hydrogen peroxide?
Nuclear physics is neat. It's a shame it's so regulated...
Now that I think about it, that's probably a good thing. Still annoying though.
|
|
|
wg48temp9
National Hazard
Posts: 786
Registered: 30-12-2018
Location: not so United Kingdom
Member Is Offline
|
|
First try to remove the MnO2 by stuffing one or more plastic or foam scouring pads in to the flask. Then add sufficient water to swirl the pad around
the flask or use a rod to force the pad/s against the surfaces that can not be reached directly. You may need a stout wire hook to fish the pads out
when your finished.
PS: Yes H2O2 will be catalytically decomposed by MnO2.
[Edited on 12/20/2020 by wg48temp9]
I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
|
|
|
aromaticfanatic
Hazard to Others
Posts: 173
Registered: 10-9-2019
Member Is Offline
|
|
Vitamin C (ascorbic acid) will work just fine. Quick and easy to get from your local store too
|
|
|
DraconicAcid
International Hazard
Posts: 4355
Registered: 1-2-2013
Location: The tiniest college campus ever....
Member Is Offline
Mood: Semi-victorious.
|
|
Quote: Originally posted by wg48temp9  | First try to remove the MnO2 by stuffing one or more plastic or foam scouring pads in to the flask. Then add sufficient water to swirl the pad around
the flask or use a rod to force the pad/s against the surfaces that can not be reached directly. You may need a stout wire hook to fish the pads out
when your finished.
PS: Yes H2O2 will be catalytically decomposed by MnO2.
[Edited on 12/20/2020 by wg48temp9] |
Rather than a scouring pad, I'd use sand or rice. I've used them for years to clean out wine bottles (and the rice may act as a reducing agent, as
well).
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
|
|
|
aromaticfanatic
Hazard to Others
Posts: 173
Registered: 10-9-2019
Member Is Offline
|
|
| Quote: Originally posted by Antigua | | Almost everything works... sodium bisulfite (so sodium metabisulfite too), dilute HCl, even some detergents with chelating agents apparentely.
|
Doesn't HCl form chlorine? I suppose in dilute solution none would really be released.
|
|
|
Deathunter88
National Hazard
Posts: 522
Registered: 20-2-2015
Location: Beijing, China
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by DraconicAcid | | Quote: Originally posted by wg48temp9 | First try to remove the MnO2 by stuffing one or more plastic or foam scouring pads in to the flask. Then add sufficient water to swirl the pad around
the flask or use a rod to force the pad/s against the surfaces that can not be reached directly. You may need a stout wire hook to fish the pads out
when your finished.
PS: Yes H2O2 will be catalytically decomposed by MnO2.
[Edited on 12/20/2020 by wg48temp9] |
Rather than a scouring pad, I'd use sand or rice. I've used them for years to clean out wine bottles (and the rice may act as a reducing agent, as
well). |
Sand will form microscopic scratches in the glass - not safe. Rice would be better.
|
|
|
RustyShackleford
Hazard to Others
Posts: 200
Registered: 10-12-2020
Location: Northern Europe
Member Is Offline
|
|
ive always used HCl to clean up MnO2. generates a bit of Cl2 but its extremely fast acting.
i guess metabisulfite would work well too, but havent tried
|
|
|
valeg96
Hazard to Others
Posts: 254
Registered: 6-4-2014
Location: Italy
Member Is Offline
Mood: Moodless
|
|
Coarse salt and just enough soapy water to make it into a thick abrasive paste. Cap and shake, and it will remove hard crusty spots without damaging
the glass like sand does. If you need it acidic, use dilute HCl. Works well even with organic solvents (e.g. black organic tars inside of RBFs), just
use a chlorinated solvent or paint thinner instead of water.
|
|
|
MidLifeChemist
Hazard to Others
Posts: 192
Registered: 4-7-2019
Location: West Coast USA
Member Is Offline
Mood: precipitatory
|
|
I would use HCl, and just do it outside if you don't want a dose of Cl2 up your nose. Good luck and let us know how it goes!
|
|
|
Bedlasky
International Hazard
Posts: 1241
Registered: 15-4-2019
Location: Period 5, group 6
Member Is Offline
Mood: Volatile
|
|
In neutral and alkaline solution yes. But in acidic solution it react with H2O2 to form Mn2+ and O2.
|
|
|
unionised
International Hazard
Posts: 5128
Registered: 1-11-2003
Location: UK
Member Is Offline
Mood: No Mood
|
|
Lemon juice also works- which is good to know if you get similar stains on your fingers.
|
|
|
TriiodideFrog
Hazard to Others
Posts: 108
Registered: 27-9-2020
Member Is Offline
|
|
Some mild acids should work quite well.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
