[some dude]

Hi,

I want to make chromium (III) citrate out of chromium (III) chloride. I would dissolve CrCl₃ in NaOH solution to get Cr(OH)₃ as a precipitate. Wash the precipitate with water and mix it with citric acid. Would that work? Is there an easier way?

[chenbeier]

This should work, easier way not known.

[some dude]

Thanks, I just had a thought: In the case of water soluble CrCl₃ hexahydrate, wouldn't it be possible to just mix it directly with citric acid in water to get chromium citrate and vaporize the residual water and HCl?

[chenbeier]

Which acid is the stronger one. The opposit would happen, if you add HCl to chromiumcitrate you would get chromium chloride and citric acid.

[some dude]

Ok, so I made chromium hydroxide using NaOH, then washed it several times and dried it. Apparently, I dried it too hot (in a stainless steel pot on the oven), as the chromium hydroxide had a nice turquoise color and now the bottom part of it turned black. Question is what is that black stuff and can I still turn it into chromium (III) citrate?

[some dude]

I just put some chromium hydroxide into dissolved citric acid... apart from a tiny bit of fizzing at the beginning, nothing happened. Do I need to increase temperature, pressure, a catalyst? Any ideas?

[shchavel]

Hi, I think it was a bad idea to heat Cr(OH)3 for drying. because it can turn to CrO(OH) by heating near 100C. Try to dry your perticipante with out heating.