Description:
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The physical makeup of an electrolysis cell is virtually identical to that of the voltaic
cell discussed in Booklet 8 of this series. Like the voltaic cell, it generally
consists of two solid electrodes (called the cathode and anode) in contact with a
suitable ionically conducting liquid or electrolyte and, in more elaborate cells, the
cathode and anode may also be separated by a porous membrane or spacer. But if
the physical construction is virtually identical, the chemistry is not. In a voltaic
cell thermodynamically favorable chemical reactions are used to generate electrical
energy, whereas in an electrolysis cell thermodynamically unfavorable chemical
reactions are induced by means of an external source of electrical energy in the
form of either a battery or a direct current (DC) electrical generator. |