ndrew Livingsto x u-lgNslk a https//www-a Designing a galvanic cell from two hal

Question

ndrew Livingsto x u-lgNslk a https//www-a Designing a galvanic cell from two half reactions standard reduction potential half-reaction +1.065 v red Br,(l) +2e 2 Br (aq) Ered +0.59 v Mino, (s) +40H (aq) Answer the following questions about this cell. Write a balanced equation for the half-reaction that L happens at the Write a balanced equation for the half reaction that happens at the Write a balanced equation for the overall reaction that powers the cell. Be sure the reaction is spontaneous as Explanation

Explanation / Answer

ANSWER

HINT: Greater the Eored valueof a half reaction greater is the tendency for reduction. Since first reaction has greater Eored than second half reaction so it will be reduction half cell(Reaction at cathode)

(A) Reduction takes place at cathode. Balanced half rection is given as

Br2(l) + 2e- ------> 2Br-(aq)

(b) Oxidation half reaction: Since the forward reaction is reduction hence backward reaction is oxidation

MnO2(s) + 4OH- (aq) -------> MnO4- (aq) + 2H2O(l) + 3e-

(C) Overall reaction: To write overall balanced reaction balance the number of electrons in two half -reactions. This can be done by multiplying reduction haf by 3 and oxidation half by 2.

3Br2(l) + 6e- ------> 6Br-(aq)

2MnO2(s) + 8OH- (aq) -------> 2MnO4- (aq) + 4H2O(l) + 6e-

-------------------------------------------------------------------------------------------

3Br2(l) + 2MnO2(s) + 8OH- (aq)  ------> 6Br-(aq) + 2MnO4- (aq) + 4H2O(l)

(D) NO. The concentration of oxidised (MnO4- ) and reduced (Br-)species is not given.

Related Questions

Navigate

• Browse (All)
• Browse N
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.