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Chemistry Forums for Students => Inorganic Chemistry Forum => Topic started by: some dude on April 13, 2020, 05:31:14 AM

Title: Turning chromium chloride into chromium citrate
Post by: some dude on April 13, 2020, 05:31:14 AM

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?

Title: Re: Turning chromium chloride into chromium citrate
Post by: chenbeier on April 13, 2020, 08:30:34 AM

This should work, easier way not known.

Title: Re: Turning chromium chloride into chromium citrate
Post by: some dude on April 13, 2020, 08:48:22 AM

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?

Title: Re: Turning chromium chloride into chromium citrate
Post by: chenbeier on April 13, 2020, 01:44:47 PM

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

Title: Re: Turning chromium chloride into chromium citrate
Post by: some dude on April 20, 2020, 08:00:28 AM

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?

Title: Re: Turning chromium chloride into chromium citrate
Post by: some dude on April 21, 2020, 12:30:35 AM

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?

Title: Re: Turning chromium chloride into chromium citrate
Post by: shchavel on May 01, 2020, 08:12:22 AM

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.