Chapter 18.8, Problem 1RCF

What is the minimum voltage needed for the electrolytic process shown in Figure 18.19?

Figure 18.19 A diagram showing the electrode reactions during the electrolysis of water. Note that the signs of the electrodes are opposite to those of a galvanic cell. In a galvanic cell, the anode is negative because it supplies electrons to the external circuit. In an electrolytic cell, the anode is positive because electrons are withdrawn from it by the battery.

$\begin{array}{cc}2{\text{H}}_2\text{O}(l)\stackrel{}{\to }{\text{O}}_2(g)+4{\text{H}}^{+}(aq)+4e^{-}& 4{\text{H}}^{+}(aq)+4e^{-}\stackrel{}{\to }2{\text{H}}_2(g)\end{array}$