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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: Stellahung1215 on December 29, 2013, 02:33:36 AM

Title: Some questions about redox reactions
Post by: Stellahung1215 on December 29, 2013, 02:33:36 AM
My textbook says that when sodium iodide solution and iron(Ⅲ) nitrate solution are mixed directly, iron(Ⅲ) ions will gain electrons.
According to the ECS, nitrate ion is a stronger oxidizing agent than iron（Ⅲ）ion.
So why do iron（Ⅲ）ions gain electrons instead of nitrate ions?
thanks
Title: Re: Some questions about redox reactions
Post by: Borek on December 29, 2013, 03:43:34 AM
How strong oxidizer pH is depends on pH. If pH is not low enough, Fe3+ can be a stronger oxidizer (although it won't exist in teh solution if pH is not low enough). This is described by Nernst equation.

Plus, sometimes redox potential of some system present in the solution is high enough, but the kinetics favors other system.
Title: Re: Some questions about redox reactions
Post by: Stellahung1215 on December 29, 2013, 09:16:41 PM
Quote from: Borek on December 29, 2013, 03:43:34 AM
How strong oxidizer pH is depends on pH. If pH is not low enough, Fe3+ can be a stronger oxidizer (although it won't exist in teh solution if pH is not low enough). This is described by Nernst equation.

Plus, sometimes redox potential of some system present in the solution is high enough, but the kinetics favors other system.

Okay, thanks. I have thought about this before but I wasn't sure.