Question

Calculate the standard electrode potential for the redox reaction: Zn(s) + Cu2+(aq) → Zn2+(aq) + Cu(s)if the standard electrode potentials for Zn2+/Zn and Cu2+/Cu half-cells are -0.76V and +0.34V, respectively.

Answer 1

To calculate the standard electrode potential for the redox reaction, we need to subtract the standard electrode potential of the anode  Zn2+/Zn  from the standard electrode potential of the cathode  Cu2+/Cu .In this reaction, Zn s  is being oxidized to Zn2+ aq , so the Zn2+/Zn half-cell is the anode. Cu2+ aq  is being reduced to Cu s , so the Cu2+/Cu half-cell is the cathode.Standard electrode potential  E  for the redox reaction = E cathode  - E anode E redox  = E Cu2+/Cu  - E Zn2+/Zn E redox  =  +0.34V  -  -0.76V E redox  = +0.34V + 0.76VE redox  = +1.10VThe standard electrode potential for the redox reaction Zn s  + Cu2+ aq   Zn2+ aq  + Cu s  is +1.10V.