Chemateur80 - 9-9-2019 at 09:14
I couldn't find a thread about this substance, so here it is.
Attempted to synthesize this by mixing oxalic acid and potassium hydroxide in a 1:2 molar ratio between acid and base.
I boiled down the mixture and upon cooling some nice crystals appeared.
The solubility of K2C2O4 in water should be around 360g/L at 20C. It's not soluble in ethanol, so I added some to
recover more oxalate, and very fine crystals crashed out immediately. They were so fine that upon filtering a lot of them passed right through.
I'm not sure that I actually made potassium oxalate, because there's not much info about this substance. Wikipedia only has an article about potassium
hydrogenoxalate.
Not sure if the crystals I have are the monohydrate either. Are there other hydrated forms?
I didn't measure the yield.
Has anyone attempted this synthesis?
Given the high solubility in water, is there any effective way of recrystallizing the oxalate? Ethanol didn't seem to work very well.
Any information about the synthesis, properties and use of potassium oxalate is welcome.
I'm planning to use it for the synthesis of potassium ferrioxalate.
teodor - 9-9-2019 at 09:41
If you use 1:2 ratio then you get K2C2O4, not a hydrated form. If you need it to make another salt it is not necessary to crystallize it, you can use
it as a solution.
[Edited on 9-9-2019 by teodor]
Tsjerk - 10-9-2019 at 08:19
Can you check the melting point? Apperantly the anhydrous salt melts at 160 and the monohydraat at 310... Sounds strange but it might be true. I think
you've got the hydrate.