NO3-(aq) + 2H+(aq) + e- ---> NO2(g) + H2O(l) Ered = +0.80 V Cu(s) ---> Cu2+(aq) + 2e- Eox = -0.34 v Ecell = Eox + Ered = 0.80 - 0.34 = + 0.46 V Solution NO3-(aq) + 2H+(aq) + e- ---> NO2(g) + H2O(l) Ered = +0.80 V Cu(s) ---> Cu2+(aq) + 2e- Eox = -0.34 v Ecell = Eox + Ered = 0.80 - 0.34 = + 0.46 V.