Cleaning your glassware

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jarlowski1

Well-known member
Joined
Dec 20, 2013
Messages
176
So if you have processed ceramic cpus before that I am almost positive you have encountered the yellow precipitant that gets stuck to you glass and won't come off. I wanted to share with you guys how I clean this up instantly. I take some 70% isopropyl alcohol and add a few flakes of potassium hydroxide to it in the beaker that has the yellow junk swirl it around to dissolve the potassium hydroxide and the yellow junk will disappear pour into proper waste container this solution is ph basic. Rinse with distilled water a couple of times and its done. Please as always use gloves and safety glasses and do this outside or in a fume hood. Hope this helps and saves some beakers :D
 
I found by accident that a small amount of stannous chloride will quickly turn the stubborn yellow Mo(?) to a beautiful royal blue and it just peels away with a little swirling of the solution.

Edit: It was ZINC not tin. Forget the stannous. Zinc chloride. Massive brain fart on my behalf.
 
UncleBenBen said:
I found by accident that a small amount of stannous chloride will quickly turn the stubborn yellow Mo(?) to a beautiful royal blue and it just peels away with a little swirling of the solution.

Aha- I learn something new every day. 8) 8)

Thanks.
 
anachronism said:
UncleBenBen said:
I found by accident that a small amount of stannous chloride will quickly turn the stubborn yellow Mo(?) to a beautiful royal blue and it just peels away with a little swirling of the solution.

Aha- I learn something new every day. 8) 8)

Thanks.

You bet.
Give it a try. Sure beats scrubbing that mess off. Getting to watch the speed of the reaction and color change is just a bonus! :wink:
 
There goes my 1/2 oz. bottles of stannous, :lol:

I used to process ceramic cpus in Dollar Tree flower vases so I could just toss them out afterwards. Even at a dollar each, I hated wasting them.
 
Shark said:
There goes my 1/2 oz. bottles of stannous, :lol:

I used to process ceramic cpus in Dollar Tree flower vases so I could just toss them out afterwards. Even at a dollar each, I hated wasting them.

Shark, no! LOL! Don't waste your prepared stannous testing solution. Just toss in enough HCl to get a good swirl in the beaker and drop in a few small pieces of cheap tin and let it react.

I found this by decanting after reducing Pd with chopped up pieces of tin drywall anchors. I happened to grab one of my yellow "scrap" beakers to decant to and poof! Yellow went blue and the beaker looked brand new.

Edit to add: I meant to post about it a few years ago, but I guess I got distracted. :oops:

Edit again: It is Zinc chloride, not tin
 
Didn't think about making in the glassware. That will save time as well as beakers.
 
You are seeing tungstic acid and the blue upon a strong reductant is something W and Mo do.

Any dilute sodium hydroxide or dilute peroxide works very well on it.

Re acidification or boiling (in case of peroxide) throws it back down.
 
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