Notice that electrons cancel, and we simply get the following net reduction reaction. Now, if we were to look up the electron potentials or the cell potentials for this reaction and this reaction, we would get the following voltages. Now, to find the net or the final cell voltage, we simply add these guys up, and we get negative 4.0
72 volts. So that means that this much voltage must be supplied to our electrolytic cell by this battery to power this reaction. So decomposition of this guy required energy. Now, other decomposition reactions are very popular.