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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: Robertsays on April 04, 2008, 09:45:55 AM

Title: ammonium iron(II) sulfate and Dichromate.
Post by: Robertsays on April 04, 2008, 09:45:55 AM

Cr2O72-  + (NH4)2SO4.Fe2SO4.6H2O -->

Can anyone help me out here?

Title: Re: ammonium iron(II) sulfate and Dichromate.
Post by: Borek on April 04, 2008, 09:53:21 AM

Please read forum rules (http://www.chemicalforums.com/index.php?page=forumrules).

Mohr's salt is dissociated in this reaction. Split it into ions, than think what is reacting with what - you have an oxidizer and a reducing agent.

Title: Re: ammonium iron(II) sulfate and Dichromate.
Post by: Robertsays on April 04, 2008, 11:35:18 AM

sorry,

Cr2O72- + 14H+ + 6e- ---> 2Cr3+ + 7H2O     (reduction)

Fe2+ ---> Fe3+ + e-      (oxidation)

so,

Cr2O72- + 6Fe2+ +  14H+ --> 2Cr3+ + 6Fe3+ +  7H2O

but do the ammonium and sulfate ions react with anything? seems too simple.

Title: Re: ammonium iron(II) sulfate and Dichromate.
Post by: Borek on April 04, 2008, 01:36:44 PM

They are just spectators. And your equation is correct :)