Tell me more about this extraction process. What did you extract the H3PO4 from, and how?
H3PO3 from potassium phosphite from antifungal spray for grasses.
IIRC it was a 1:1 or 1:2 volume of phosphite solution to hcl aq
Upon addition of hcl aq, kcl precipitated..
This was filtered, solution was heated, more precipitated, process was repeated several times until no more kcl precipitated…
Resulting solution was boiled down till no more HCL smell
Then isopropyl alcohol that I had boiled (To concentrate alcohol content!!) - was added
This frothed up a bit, I then reduced the mixture even more.
I was left with a syrup like consistently that I tried freezing, didn’t give it much time in the freezer, it didn’t solidify, and I disposed of
it.
Mind you, I did this over a camp fire/Al clad frying pan atop coals, with beakers on top the frying pan.
It was messy, there was a lot of splattering, yields sucked.
Thought I had needed tall form beakers, but that would have made evaporation less.
Next time it will be Erlenmeyer’s with tubing shoved in to route fumes/evaporation products away.
The solution will be reduced outside atop single burner propane stove, I’ll take care in how much heat is applied to prevent splattering
— or maybe ill use a few beakers and stir rods to prevent splattering,
Then for the final step reduce on an erlenmeyer with tubing attached to route alcohol vapors away from the flame.
At the time I didn’t understand how changing the heat would reduce splattering somehow, though I had cooked spaghetti sauce many times…
Itd be better with utility hookups / vacuum.
But, I think it’s good to run this outdoors…
Just not sure how to get the last trace of water out now ( suggestions appreciated!)
Also, HCL gas can be bubbled through the phosphite solution to reduce the volume of water that needs to be reduced vs using aq HCL..
If anyone has any suggestions for the procedure of making and drying H3PO3, I’d love to here them.
..
Additional question. Could a lump some amount of phosphine gas be produced if this H3PO3 were over heated, or would small bubbles of phosphine be
produced in the beaker of reducing H3PO3 and burst on the surface?
Is H3PO3 ignitable? — I didn’t see this, my jar caught fire several times from alcohol vapors catching from atop the open beaker- it was
extinguished. I here it’s more dangerous reducing the final amount of water, but at first, I here, and believe, that you can boil the f*** out of
the solution over open flame, until, the water volume gets greatly reduced that is.
Observations-
Iirc some burned with a green flame,
Upon addition of HCL to the phosphite solution, it smelled like matches..
Looking for input on this,
Thanks guys Yttrium2 - 8-10-2022 at 11:50
The caveat with the procedure I heard was the repeated boiling and filtration of the kcl, I was told to do it 6 times…
Is there a better way to remove the precipitated kcl?
If it’s left at the bottom of the beaker, what would happen if one tried reducing the solution with all the kcl at the bottom??
