octave - 16-3-2008 at 10:04
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 - 16-3-2008 at 10:10
try KOH soln.
octave - 16-3-2008 at 10:20
I was thinking I should but it should have already been basic from neutralization.I have messed up somewhere in these cleaning techniques.
YT2095 - 16-3-2008 at 11:07
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.
vulture - 16-3-2008 at 14:22
Possibly aluminiumhydroxide. If that's the case, you're in for a real treat.
not_important - 16-3-2008 at 19:46
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 - 18-3-2008 at 01:12
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).