Asked by Matt
For the following electrochemical cell:
Fe(s)/Fe2+(aq)//MnO4–(aq), Mn2+(aq)/ Pt(s)
Which letter corresponds to the correct balanced chemical equation in an acidic solution?
A. 2Mn2+(aq) + 8H2O(l) + 5Fe2+ ==> (aq)5Fe(s) + 16H+(aq) + 2MnO4–(aq)
B. 5Fe(s) + 16H+(aq) + 2MnO4–(aq)2Mn2+(aq) + 8H2O(l) + 5Fe2+(aq)
C. Fe(s) + 8H+(aq) + MnO4–(aq) ==> Mn2+(aq) + 4H2O(l) + Fe2+(aq)
D. Fe(s)+8H+(aq)+MnO4–(aq)+Pt2+(aq)==> Mn2+(aq)+4H2O(l)+Fe2+(aq)+Pt(s)
E. Mn2+(aq)+4H2O(l)+Fe2+(aq)+Pt(s) ==>Fe(s)+8H+(aq)+MnO4–(aq)+Pt2+(aq)
What reaction is occurring at the cathode?
A. 5e– + 8H+(aq)+MnO4–(aq)==>Mn2+(aq) +4H2O(l)
B. Fe2+(aq) + 2e– ==> Fe(s)
C. Fe(s)==>Fe2+(aq) + 2e–
D. Mn2+(aq) + 4H2O(l)==>5e– + 8H+(aq) + MnO4–(aq)
E. Pt(s)==>Pt2+ + 2e
Fe(s)/Fe2+(aq)//MnO4–(aq), Mn2+(aq)/ Pt(s)
Which letter corresponds to the correct balanced chemical equation in an acidic solution?
A. 2Mn2+(aq) + 8H2O(l) + 5Fe2+ ==> (aq)5Fe(s) + 16H+(aq) + 2MnO4–(aq)
B. 5Fe(s) + 16H+(aq) + 2MnO4–(aq)2Mn2+(aq) + 8H2O(l) + 5Fe2+(aq)
C. Fe(s) + 8H+(aq) + MnO4–(aq) ==> Mn2+(aq) + 4H2O(l) + Fe2+(aq)
D. Fe(s)+8H+(aq)+MnO4–(aq)+Pt2+(aq)==> Mn2+(aq)+4H2O(l)+Fe2+(aq)+Pt(s)
E. Mn2+(aq)+4H2O(l)+Fe2+(aq)+Pt(s) ==>Fe(s)+8H+(aq)+MnO4–(aq)+Pt2+(aq)
What reaction is occurring at the cathode?
A. 5e– + 8H+(aq)+MnO4–(aq)==>Mn2+(aq) +4H2O(l)
B. Fe2+(aq) + 2e– ==> Fe(s)
C. Fe(s)==>Fe2+(aq) + 2e–
D. Mn2+(aq) + 4H2O(l)==>5e– + 8H+(aq) + MnO4–(aq)
E. Pt(s)==>Pt2+ + 2e
Answers
Answered by
DrBob222
What do you think and why?
#2. Reduction occurs at the cathode (the + charged electrode).
#2. Reduction occurs at the cathode (the + charged electrode).
Answered by
Matt
#1, Fe(s) is on the left, so it's anode; Pt(s) is on the right, it's a cathode...so the rxn should be D.
#2: B because Fe is gaining electrons, making it a reduction=cathode.
#2: B because Fe is gaining electrons, making it a reduction=cathode.
Answered by
DrBob222
Right on the anode and cathode. If D is the correct answer, why doesn't it have Fe in it. There's no Fe in D. And you need an Fe going to Fe^+2 + 2e.
Answered by
Matt
no, there's Fe in D for the first question..Fe(s)+8H+(aq)+MnO4–(aq)+Pt2+(aq)==> Mn2+(aq)+4H2O(l)+Fe2+(aq)+Pt(s)
Answered by
DrBob222
You're right and I'm wrong. I was looking at the second set of answers and not the first. So Fe is on the left and it is the anode. So now what reaction is occurring at the Pt electrode? Obviously it's the other half cell, which is______?
Answered by
Matt
Pt is functioning as a cathode
- D shows that Pt is cathode and Fe as anode. I don't understand why H+ and water are in the reaction
so my answers
1)D
2)B
- D shows that Pt is cathode and Fe as anode. I don't understand why H+ and water are in the reaction
so my answers
1)D
2)B
Answered by
DrBob222
D is correct for #1. For #2, isn't the correct answer A? Pt is the cathode (+ electrode where reduction occurs) and that is the MnO4^- reaction going to Mn^+2.
Answered by
RoRo
the answer is actually B and A
Answered by
yi
isn't Pt just functioning as an electrode?
Answered by
UCI Student
answer is B and A