-Use thee following reduction half-reactions and standard reduction potentials f

Question

-Use thee following reduction half-reactions and standard reduction potentials for this question.

Ag+ (aq) + e- Ag(s) E = 0.7996 V

Cu2+(aq) + 2e- Cu(s) E = 0.342 V

Al3+(aq) + 3e- Al(s) E = -1.6632 V

i. To set up this reaction as a battery, which half-reaction should be used as the cathode and which as the anode?

ii.What’s the calculated value of Ecell for the battery (show your calculation)?

iii. Write the oxidation half-reaction, the reduction half-reaction and the overall reaction taking place. Make sure the half-reactions are balanced for electrons, so that the number of electrons in each half reaction is the same before the half-reactions are added together

Explanation / Answer

1) In the above data, Ag+ shows +0.7996V . So , it acts as cathode and Al+3 shows -1.6632V and it acts as anode.

According to electrochemical series, the metals which posses lower electrode potential acts as anode and high reduction potential acts as cathode. so above data lower is -1.6632V,Al+3 and higher is +0.7996,Ag+

2) Electode potential,Eo= E (cathode) - E (anode)

= 0.7996-(-1.6632)

= 2.46V

3) Anode: Oxidation: Al -----------> Al+3 + 3e-

Cathode:reduction: 3Ag+ + 3e- ----------> 3Ag

Redox reaction Al +  3Ag+ + ----------> 3Ag +Al+3

Related Questions

Navigate

• Browse (All)
• Browse #
• Subjects

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