octave
Harmless
Posts: 39
Registered: 4-11-2007
Member Is Offline
Mood: Working.
|
|
Somthing staining my flask
Hello all!
Recently I have decided to do experiments with reverse Friedel Crafts on toluene, and my first order of business was to make aluminum chloride. The
reaction was with HCl and Al foil and everything went fine and dandy. Afterwards (filtering and everything) I neutralized my flask with NaHCO3 and
decided to wash it when I woke up the next day. Well when I washed it there was a crystalline stain all up and down the walls of the flask. Here are
some things I've tried to do:
-Wash with water and soap 5 or so times(letting it sit for upwards of 20 minutes).
-Swirl wash with methanol for 5 or so minutes of constant swirling.
I have tried using some dilute acetic acid to get it out(as I am out of both HCl and H2SO4) I let it sit for 30 minutes and still no change.
Any suggestions?
|
|
|
YT2095
International Hazard
Posts: 1091
Registered: 31-5-2003
Location: Just left of Europe and down a bit.
Member Is Offline
Mood: within Nominal Parameters
|
|
try KOH soln.
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
|
|
|
octave
Harmless
Posts: 39
Registered: 4-11-2007
Member Is Offline
Mood: Working.
|
|
I was thinking I should but it should have already been basic from neutralization.I have messed up somewhere in these cleaning techniques.
|
|
|
YT2095
International Hazard
Posts: 1091
Registered: 31-5-2003
Location: Just left of Europe and down a bit.
Member Is Offline
Mood: within Nominal Parameters
|
|
well, from what you`v said, I can`t think of Anything in there that a KOH soln wouldn`t take out.
or NaOH for that matter.
the most insoluble thing possible would be sodium or potassium aluminate, and it is soluble.
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
|
|
|
vulture
Forum Gatekeeper
Posts: 3330
Registered: 25-5-2002
Location: France
Member Is Offline
Mood: No Mood
|
|
Possibly aluminiumhydroxide. If that's the case, you're in for a real treat.
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
|
|
|
not_important
International Hazard
Posts: 3873
Registered: 21-7-2006
Member Is Offline
Mood: No Mood
|
|
Acetic acid isn't going to do much to Al(OH)3, the likely bases of the gunk. You'll need strong HCl, hardware store grade. Pour some in, loosely
stopper, swirl to wet all the gunk, let sit for a few minutes; repeat swirling as needed, possibly with gental warming if really stubborn.
Alkali strong enough to dissolve Al(OH)3 and kip will be strong enough to etch glass a little, strong acid is the better choice.
|
|
|
woelen
Super Administrator
Posts: 8027
Registered: 20-8-2005
Location: Netherlands
Member Is Offline
Mood: interested
|
|
Yep, HCl is the best choice. It also works much better than H2SO4, because it has the added effect of complexing Al(3+) ions and makes dissolving the
white material even easier. I expect that you get rid of the white crap within a ferw minutes when you use conc. HCl (25% or better).
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
