To calculate the standard electrode potential E for the overall reaction, we need to determine which half-reaction is being reduced and which is being oxidized. Then, we can use the standard reduction potentials given to find the E for the overall reaction.In the overall reaction:2H aq + Fe aq H g + Fe aq We can see that:- Hydrogen ions H are gaining electrons to form hydrogen gas H , so this half-reaction is being reduced.- Iron III ions Fe are losing an electron to form iron II ions Fe , so this half-reaction is being oxidized.Now, we can use the standard reduction potentials given for each half-reaction:Reduction half-reaction: 2H aq + 2e H g E = 0.00VOxidation half-reaction: Fe aq + e Fe aq E = +0.77VSince the reduction half-reaction is already given, we don't need to change it. However, we need to reverse the oxidation half-reaction to represent the actual process occurring in the overall reaction:Reversed oxidation half-reaction: Fe aq Fe aq + eWhen we reverse the half-reaction, we also need to change the sign of the standard reduction potential:Reversed oxidation half-reaction E: -0.77VNow, we can add the standard reduction potentials of the two half-reactions to find the E for the overall reaction:E overall = E reduction + E reversed oxidation E overall = 0.00V + -0.77V E overall = -0.77VSo, the standard electrode potential E for the overall reaction at 298K is -0.77V.