Oxalic Acid, does it lose potency over time?

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gorfman6154

Well-known member
Joined
Jan 5, 2008
Messages
86
Location
Washington State
Hello all.
I have an opportunity to aquire a large bag (approx 30#) of Oxalic Acid. The only problem is that it has been sitting in a sealed plastic bag, in a moist enviroment. It was a solid clump, until i smacked it with a mallet. Which is always fun :lol: . It broke apart nicely into soft grainy crystals, sort of like the texture of brown sugar. I'm worried that the texture might be wrong.

View attachment 1

My dilemma, do you think that it might still be usable? If so, what would be the best way to test it? Besides trying it out by precipitating Gold. :roll: Which i will do, if the Gold Masters of this Forum say it's ok.

If, a big IF, it is still usable i would offer some up for free, for testing, or experiments to our resident experts, if they so desire.

Hoping to get a response. Thanks all.
Gorfman
 
qst42know said:
I found this list for shelf life of assorted chemicals. 5 years for oxalic.

http://www.romil.com/Shelf_Life_SAR.pdf
Click to expand...

Thanks for the link qst42know. All i could find out is that it's been partially used, and resealed, and been hiding in a back corner of the plant for at least 3 years.

I'll give this thread a few days, and if nothing better comes up, try a small size test, w/ some foils i've just dissolved in HCL/CL. Just as a proof of viability.

And i do know that Oxalic Acid is best used to drop from clean solutions.
I'm glad i put out our new ebay box, before i took the photos :mrgreen: .

Thanks again, Gorfman
 
Here ya go:

Titration of Oxalic Acid with Sodium Hydroxide.

This is your basic Chemistry procedure to demonstrate how to do a Titration:

http://employees.oneonta.edu/kotzjc/LAB/ABEquiv_Expt.pdf
 
Shelf life for some chemicals is a load of bunk. Unlike food, we're not looking for a particular flavor or something. It is an issue for ethers and some others, but not oxalic acid. Oxalic acid is just one small step away from becoming CO2 by oxidation, which is why it's a good reducing agent. As for "potency," the clumping is surely caused by some water being around.

There are two forms available, the anhydrous and the dihydrate, with the dihydrate being the most common form. There is a significant difference in weight per mole between the two. What you have is almost surely the dihydrate with a bit more water around. It doesn't take much to turn powders into great bloody rocks. I'd just crush it back to a powder and use it as is. You may need slightly more than usual to account for the little bit of extra water weight.
 
gorfman6154 said:
qst42know said:
I found this list for shelf life of assorted chemicals. 5 years for oxalic.

http://www.romil.com/Shelf_Life_SAR.pdf
Click to expand...

Thanks for the link qst42know. All i could find out is that it's been partially used, and resealed, and been hiding in a back corner of the plant for at least 3 years.

I'll give this thread a few days, and if nothing better comes up, try a small size test, w/ some foils i've just dissolved in HCL/CL. Just as a proof of viability.

And i do know that Oxalic Acid is best used to drop from clean solutions.
I'm glad i put out our new ebay box, before i took the photos :mrgreen: .

Thanks again, Gorfman
Click to expand...

I didn't know Sand has a shelf life of 5 Years. :mrgreen:

Someone is trying to sell chemicals.
 
Alright, so I didn't edit it for content.

Just reported what I found.

I wonder what they get for 50 grams of "Reagent Grade Sand" :?: :lol:


Must be for those fat wallet research grants Lou had mentioned a while back.
 
qst42know said:
Alright, so I didn't edit it for content.

Just reported what I found.

I wonder what they get for 50 grams of "Reagent Grade Sand" :?: :lol:


Must be for those fat wallet research grants Lou had mentioned a while back.
Click to expand...

Way too much. http://www.sigmaaldrich.com/catalog/ProductDetail.do?lang=en&N4=274739|SIAL&N5=SEARCH_CONCAT_PNO|BRAND_KEY&F=SPEC

If that doesn't work, just pull up sigma aldrich's site and search for sand. It really depends on how fat your wallet is. The only reason you'd *buy* reagent grade sand is because it's standardized. That won't change with age though. :lol: Sand from different localities may have different mineral profiles and if it's being used in an experiment, that might alter the outcome. The place I worked over the summer had some. I assume it was being used for heavy metals adsorption experiments, which would be highly sensitive to mineral content of the sand.

In our undergrad research lab, some of the stuff we're using is from the early 90s and it's still in good shape and reacts as expected.
 
If someone wants to replicate your results, they should use the exact same reagents. So make a deal with the chemical company. Everyone has to buy their sand.
What a racket.
 
Only in a few circumstances is it a good idea to buy a specific reagent from a specific company. For the most part, they're all the same. Over the years, there are cases I can think of where one specific company's product was superior to another; however, this is only on very special reagents or on biologics (i.e. serums).


As far as the oxalic acid goes... it will be absolutely fine to use. Just remember it's probably the dihydrate. Clumping is fine...it's going to be dissolved in boiling hot water anyways.

And yes, it is quite toxic, so please don't eat it.
 
I would like to thank all of the members who posted replies. This is the awesome power of an open forum, everyone comes up with a different perspective of the same question.

I decided i will wait until i have my complete lab setup to carry out any experiments. I'm still working on a fume scrubber and exhaust fan.


Lou said:
As far as the oxalic acid goes... it will be absolutely fine to use. Just remember it's probably the dihydrate. Clumping is fine...it's going to be dissolved in boiling hot water anyways.
Click to expand...

Thanks for the confirmation.


qst42know said:
I wonder what they get for 50 grams of "Reagent Grade Sand"
Click to expand...

I wonder how much it would be to fill my crockpot? :mrgreen:

Best of luck to all, Gorfman
 
Lou said:
Only in a few circumstances is it a good idea to buy a specific reagent from a specific company. For the most part, they're all the same. Over the years, there are cases I can think of where one specific company's product was superior to another; however, this is only on very special reagents or on biologics (i.e. serums).


As far as the oxalic acid goes... it will be absolutely fine to use. Just remember it's probably the dihydrate. Clumping is fine...it's going to be dissolved in boiling hot water anyways.

And yes, it is quite toxic, so please don't eat it.
Click to expand...
You mean I can't sprinkle it on my matza balls? 8)
 

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