Question

A voltaic cell is constructed using the following half-reactions: Ag+(aq) + e- ---> Ag(s) EoAg+ = +0.80 V Cu2+(aq) + 2e- ---> Cu(s) EoCu2+ = +0.34 V Determine the cell reaction and the standard cell potential.

Answer 1

- Standard reduction potential of Ag/Ag⁺ is 0.80 v and that of Cu⁺²(aq)/Cu⁰ is +0.34 V.
- The couple with a greater value of standard reduction potential will oxidize the reduced form of the other couple.
Ag⁺ will be reduced to Ag(s) and Cu⁰ will be oxidized to Cu²⁺
Anode reaction: Cu⁰(s) →  Cu²⁺ + 2 e⁻     E⁰ = +0.34 V
Cathode reaction: Ag⁺(aq) + e → Ag(s)     E⁰ = +0.80 V 
Cell reaction: Cu⁰(s) + 2 Ag⁺(aq) → Cu⁺²(aq) + 2 Ag⁰(s)
E⁰ cell = E⁰ cathode + E⁰ anode
            = 0.80 + (-0.34) = + 0.46 V