How to Selectively Reduce Fe(III) Without Affecting UO22+?

  • Thread starter Thread starter Questions_14
  • Start date Start date
Click For Summary

Discussion Overview

The discussion focuses on the challenge of selectively reducing Fe(III) to Fe(II) without affecting UO22+. Participants explore potential chemical reactions and their standard reduction potentials to find a suitable method for this selective reduction.

Discussion Character

  • Technical explanation
  • Debate/contested

Main Points Raised

  • Simon seeks advice on methods to selectively reduce Fe(III) without reducing UO22+.
  • One participant suggests using the standard reduction potentials of the reactions, noting that the potential for the Fe3+ to Fe2+ reduction is higher than that for UO22+ to U4+, which could allow for selective reduction under specific conditions.
  • Another participant questions the presence of O2- in water solution, indicating that the proposed reaction may not occur as suggested.
  • A later reply acknowledges the concern about O2- and clarifies that the focus was on the reduction potential, not the exact reaction mechanism.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of the proposed reactions and the accuracy of the reduction potentials, indicating that multiple competing views remain without a consensus on the best approach.

Contextual Notes

There are unresolved aspects regarding the exact reactions that occur in solution and the implications of using standard reduction potentials in practical applications.

Questions_14
Messages
1
Reaction score
0
Hi All,

I have been searching the web for days now, trying to find a way to selectively reduce Fe(III) to Fe(II) without reducing the uranium oxide (UO22+) present, and was hoping someone with more of a chemistry background could give me some advice on what to try/do.


Cheers
Simon
 
Last edited:
Chemistry news on Phys.org
Hi, and welcome to PF!

I did some searching on my own, and I think this works.

The reaction UO2+ + e- → U4+ + 2O2- has a standard reduction potential of 0.38 V.

The reaction Fe3+ + e- → Fe2+ has a standard reduction potential of 0.771 V.

Since the iron reaction has a higher potential, you can construct a cell where the anode reaction has a potential higher than 0.38 but lower than 0.771, which will then be spontaneous for the iron reaction but not for the uranium reaction.

http://www.webelements.com/uranium/compounds.html
 
espen180 said:
The reaction UO2+ + e- → U4+ + 2O2- has a standard reduction potential of 0.38 V.

O2- in water solution? That's not the reaction you will observe.

--
 
No, I realize that. Each oxygen ion will immediately deprotinate a water molecule making OH-.

All I really wanted from the reaction was the reduction potential, but you are right of course, it's not the right picture.
 

Similar threads

Replies
4
Views
3K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 9 ·
Replies
9
Views
5K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 19 ·
Replies
19
Views
10K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
Replies
1
Views
3K
  • · Replies 16 ·
Replies
16
Views
3K
Replies
6
Views
39K