Sciencemadness Discussion Board

Which one is BaCl2 (or maybe both are?)

RU_KLO - 14-10-2024 at 14:41

I need barium chloride for sulfate analisys.
As its difficult for me to get it, Im processing baryte rock powder (very cheep used as mud mask in cosmetics)

It was bought as a light brown powder.
Processed this way:
(Note: I kept the different filtrates to (in a future) check what other substances it has.)

1) boiled in water (to remove water soluble salts.) Also the stirrer removed some Iron (as black magnetic powder)
2) acidified with HCl (first a lot of effervecense) till acid. (probably a lot of carbonates).
3) decanted, and then boiling again in HCl. Idea: to remove soluble chlorides - yellow filtrate - probably Iron contamination.
4) decanted and then boiling again in 30% H2SO4, to remove soluble sulfates.

after this the precipitate was very light brown, but not white.

this precipitate was boiled (refluxed for one hour) with double the molarity of sodium carbonate to transform the sultafe in carbonate.

Washed several times (more like by decanting than filtering) to remove excess sodium carbonate.

Then added HCl to transform the carbonate to chloride.
Filtered, and the filtrated reduced by heat to dryness. - of white powder.
Added some water to disolve it to cristallize. (the solution was green yellow - iron contamination)

Currently is cristallizing. Here is a picture.
Found 2 types of cristalls. one like a square and the other as needles.
From wikipedia it stated as:
Crystal structure:
PbCl2-type orthorhombic (anhydrous) square like
monoclinic (dihydrate) - needle like

(of course I dont think is anhydrous. So probably is the monoclinic.)

After checking the picture, which one do you think is BaCl2
What could be the other one?
Or maybe both are BaCl2.....






barrium chloride.jpg - 189kB

Boffis - 16-10-2024 at 08:36

Hi RU_KLO: I have prepared barium chloride on several occasion, generally from witherite BaCO3 which is abundant around where I live on the dumps of old lead mines. When evaporation occurs fairly slowly large thin diamond-shaped tablets result like the ones outlined in red. I have no idea what the needles could be but since they look fairly lareg maybe you could pick a few out and test them separately.