andyloris
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Cleaning chromium(III) oxide stains from a flat bottom flask
I tried disolving chromium(III) oxide in hydrochloric acid, however it didn't work and I was left with chromium(III) oxide stains in my flat bottom
flask.
How do I clean them ?
Thanks in advance !
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andyloris
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Guess my flask is gonna stay green forever ...
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Bedlasky
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I don't have experience with this issue, but when I needed clean something from Fe(OH)3, oxalic acid always worked very well. Try that. Or maybe
bleach will help - it oxidize Cr2O3 to water soluble chromate. If Cr2O3 is deposited as a thin layer on the glass, you can try 40% NaOH - it eat away
very small amount of glass and Cr2O3 won't stick to it anymore (and maybe even dissolve in NaOH).
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clearly_not_atara
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Could try forming the oxalate complex with refluxing potassium hydrogen oxalate?
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andyloris
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Thanks !
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macckone
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If hypochlorite does not work, there is always chlorate and bromate.
Depending on how tenacious the chromium oxide is, bromate may be the agent you need.
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