Presto
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#1
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#1
Can someone pls tell me why can't it be C instead?
All catalyst are regenerated and they asked about effective catalysis...

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BobbJo
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#2
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You have to consider the type of catalysis and mode of action of the catalyst. It is a homogeneous catalysis:
2Fe3+ + 2I- -> 2Fe2+ + I2
2Fe2+ + S2O82- -> 2Fe3+ + 2SO42-

I- donates electrons to Fe3+ to form Fe2+. Fe2+ donates electrons to S2O82-.

There is no adsorption so talking about "active sites on which the reaction can occur" is not relevant hence A.

A is true. Use electrode potentials to see that
2Fe3+ + 2I- -> 2Fe2+ + I2
2Fe2+ + S2O82- -> 2Fe3+ + 2SO42-
are feasible reactions
B is not relevant.
C is not true because it is not a heterogeneous catalysis. There is no adsorption
D is not true (reduction) O in the peroxo linkage goes from -1 to -2 oxidation state in SO42- and it is Fe2+ which is reducing the peroxodisulfate ions, not Fe3+
2Fe2+ + S2O82- -> 2Fe3+ + 2SO42-
Last edited by BobbJo; 1 year ago
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Pigster
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#3
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(Original post by BobbJo)
D is true
2Fe2+ + S2O82- -> 2Fe3+ + 2SO42-
I might not have woken up fully yet, but doesn't your equation show Fe2+ reducing S2O82- rather than Fe3+ oxidising S2O82-?
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BobbJo
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#4
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(Original post by Pigster)
I might not have woken up fully yet, but doesn't your equation show Fe2+ reducing S2O82- rather than Fe3+ oxidising S2O82-?
thank you, my mistake
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Presto
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#5
Report Thread starter 1 year ago
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(Original post by BobbJo)
You have to consider the type of catalysis and mode of action of the catalyst. It is a homogeneous catalysis:
2Fe3+ + 2I- -> 2Fe2+ + I2
2Fe2+ + S2O82- -> 2Fe3+ + 2SO42-

I- donates electrons to Fe3+ to form Fe2+. Fe2+ donates electrons to S2O82-.

There is no adsorption so talking about "active sites on which the reaction can occur" is not relevant hence A.

A is true. Use electrode potentials to see that
2Fe3+ + 2I- -> 2Fe2+ + I2
2Fe2+ + S2O82- -> 2Fe3+ + 2SO42-
are feasible reactions
B is not relevant.
C is not true because it is not a heterogeneous catalysis. There is no adsorption
D is not true (reduction) O in the peroxo linkage goes from -1 to -2 oxidation state in SO42-
2Fe2+ + S2O82- -> 2Fe3+ + 2SO42-
Thank you soo much!
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