Final answer:
In electrochemical cells, when two half-cells are connected, electrons will flow from the anode to the cathode where the half-reaction with the stronger tendency, as indicated by more positive electrochemical potentials, will occur.
Step-by-step explanation:
When two half-cells are connected, the electrons will flow in such a way that the half-reaction with the stronger tendency to gain electrons (reduction) or lose electrons (oxidation) will occur. In the context of electrochemistry, we generally consider the half-cell with the stronger or more positive electrochemical potential to have a stronger tendency to undergo the reduction half-reaction. Thus, the half-reaction with the stronger oxidizing agent (more positive reduction potential) at the cathode will take place, and that with the stronger reducing agent (more negative reduction potential) will occur at the anode. Applying this to standard electrode potentials, the redox reaction is predicted to be spontaneous if the oxidant's entry in the standard electrode potentials table is above the reductant's entry, meaning the reaction at the cathode is stronger in terms of reducing capacity.