AAMC CBT 3 PS 46 (REDOX troubles)

[sudo]

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Problem:

So, hydrogen is being reduced (making it the oxidizing agent). How does that not make it's SO42- counterpart the reducing agent??

Did anyone else get mixed up on this problem as well? 😡

 

[411309]

This is actually kind of a trick question. H2SO4 is a strong acid so it disassociates. So the actual equation is Fe + 2H + SO4 -----> H2 + FeSO4. Since Fe is getting oxidized it must be the reducing agent.

 

[aspiringdoc09]

The full chemical equation will have iron sulfate (FeSO4) on products side with hydrogen gas. The sulfate ion has a -2 oxidation state on both reactants and products sides so it is not the correct answer. Like they said hyrodgen goes from +1 on reactant side to 0 on product side, so it is reduced and becomes the oxidant. Therefore, only Fe (s) acts as reducing agent because it goes form 0 oxidation state (elemental) on reactant side to +2 on products sides when in FeSO4 molecule.

 

[somefun]

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[sudo]

The full chemical equation will have iron sulfate (FeSO4) on products side with hydrogen gas. The sulfate ion has a -2 oxidation state on both reactants and products sides so it is not the correct answer. Like they said hyrodgen goes from +1 on reactant side to 0 on product side, so it is reduced and becomes the oxidant. Therefore, only Fe (s) acts as reducing agent because it goes form 0 oxidation state (elemental) on reactant side to +2 on products sides when in FeSO4 molecule.

Ahhh, got it. I wasn't paying attention to the oxidation state of the SO4 on the products side. Thanks!