Sciencemadness Discussion Board

Hydrogen Fluoride from copper salt (!!)

Antiswat - 21-7-2021 at 06:55

Copper(II) fluoride is slightly soluble in water, but starts to decompose when it is in hot water, producing basic F− and Cu(OH) ions.

https://en.wikipedia.org/wiki/Copper(II)_fluoride

i was messing around with figuring out the most doable way to first up purify fluoride from welding slag/flux but came across this
this however, could be used as an acid-free way of forming HF

from welding slag my idea is to first react it all with H2SO4, forming HF and metal sulfates
then ppt the copper fluoride using CuAc, the sulfates stay in solution

then another neat trick ive come around is that copper salts when heated with NaOH forms the corresponding sodium salt along with CuO, CuO from decomposition of formed Cu(OH)2, a true lifehack of a reaction when dealing with inorganic chemistry, especially because copper salts have oftenly opposite solubilities of other metal salts.

Bedlasky - 21-7-2021 at 07:35

You cannot produce HF just from CuF2 and hot water. You need strong acid for this.

Antiswat - 22-7-2021 at 12:42

you might be right, the guy who experienced this was using it for electrolysis
coming to think of this whole HF to sodium fluoride, NaOH could be used as dessicant to suck up the HF fumes, cryolite seems like a good source of fluoride. this would avoid getting into contact with HF fumes