Table 1 Cell Type Lithium-iodine Zinc-mercury Operating Cell Potential for Commercial Batteries, E (V) +2.80 +1.35 Table 2 Standard Reduction Potential, E” (V) Half-Reaction Zn(OH).1? +2e → Zn +40H Zn(OH), +2e → Zn +20H HgO + H2O +2e – Hg + 2OH 0, + 2 H2O + 4e 40H – 1.20 |–1.25 +0.10 +0.40 Pacemakers are electronic devices that help regulate the heart rate. Currently, lithium-iodine cells are commonly used to power pacemakers and have replaced zinc-mercury cells. Table 1 provide the operating cell potential, E, for each cell. Table 2 provides the standard reduction potentials for several half-reactions related to zinc-mercury and zinc-air cells. On average, after one year of operation, the potential of a lithium-iodine cell decreases by 1%-2%. Which of the following best helps to explain the cause for the decrease in cell potential?

HgO + H2O +2e Hg + 20H O2 + 2H2O + 4e + 40H +0.10 +0.40 Pacemakers are electronic devices that help regulate the heart rate. Currently, lithium-iodine cells are commonly used to power pacemakers and have replaced zinc mercury cells. Table 1 provides the operating cell potential, E, for each cell. Table 2 provides the standard reduction potentials for several half-reactions related to zinc-mercury and zinc air cells. On average, after one year of operation, the potential of a lithium-iodine cell decreases by 1%-2%. Which of the following best helps to explain the cause for the decrease in cell potential? E = E” cathode) – Ered (anode), and as the cell operates, Ered cathode) decreases (B E cell = Ered (cathode) – Ered (anode), and as the cell operates, Ered (anode) increases. C) Ecell = Eolt In Q and as the cell operates, Q decreases (D) Ecell = Ecell- in Q, and as the cell operates, Q increases.