Chemistry - Electrolysis
This resource covers electrolysis. During electrolysis electrical energy
is converted to chemical energy. Electrical energy is used to bring about a
chemical reaction that will not occur spontaneously. Electrolysis involves
passing an electrical current through an electrolyte. The following pages
explore: the electrolysis of molten NaCl, the Downs cell and industrial
production of sosium, electrolysis of aqueous solutions, electroplating and
An electrolyte is a medium in which electrolytic conduction (the movement
of cations and anions in opposite directions) may occur under the influence
of an applied electrical potential. Electrolytes are molten ionic compounds
and aqueous solutions of ionic or polar substances.
In a galvanic cell, the oxidation process occurring at the anode produces
electrons, thus making the anode negative.
In an electrolytic cell, the external power source drags electrons off the
anode electrode thus making it positive.
Oxidation occurs at that anode because the electrons dragged off by the
external power source must be replaced.
An animation of the Daniell electrolytic cell.
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