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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: Rutherford on August 31, 2012, 01:18:55 PM

Title: Chromium oxidation
Post by: Rutherford on August 31, 2012, 01:18:55 PM

I know that in acidic solution Cr₂O₇^2- and CrO₄^2- get reduced to Cr³⁺, but under what conditions Cr³⁺ gets oxidized to CrO₄^2-, and what conditions are required to make Cr₂O₇^2-?

Title: Re: Chromium oxidation
Post by: Borek on August 31, 2012, 02:02:41 PM

Quote from: Raderford on August 31, 2012, 01:18:55 PM

what conditions are required to make Cr₂O₇^2-?

Just a matter of pH:

2CrO₄^2- + 2H⁺ ::equil:: Cr₂O₇^2- + H₂O

Title: Re: Chromium oxidation
Post by: Rutherford on August 31, 2012, 03:58:27 PM

Then, acidic solution=dichromate, basic solution=chromate?

Title: Re: Chromium oxidation
Post by: Borek on August 31, 2012, 05:00:32 PM

Or mixture of both.

Title: Re: Chromium oxidation
Post by: Rutherford on September 01, 2012, 03:54:17 AM

Okay, thanks.