16-4. Consider the following electrolysis reactions. Cathode: H₂O(l) + e¯ = H2(g, 1.0 bar) + OH+ (aq, 0.10 M) Anode: Br (aq, 0.10 M) = = 1½ Br₂(1) + e (a) Calculate the voltage needed to drive the net reaction if current is negligible. (b) Suppose that the cell has a resistance of 2.0 and a current of 100 mA. How much voltage is needed to overcome the cell resis- tance? This is the ohmic potential. (c) Suppose that the anode reaction has an overpotential of 0.20 V and that the cathode overpotential is 0.40 V. What voltage is needed to overcome these effects combined with those of parts (a) and (b)? (d) Suppose that concentration polarization occurs. [OH-], at the cathode surface increases to 1.0 M and [Br], at the anode surface decreases to 0.010 M. What voltage is needed to overcome these effects combined with those of (b) and (c)?