Explaion Faraday’s Laws of Electrolysis - QS Study
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The factors affecting the quantities of matter liberated during the process of electrolysis were investigated by Faraday.

First Law: The mass of a substance liberated at an electrode is directly proportional to the charge passing through the electrolyte.

If an electric current I is passed through an electrolyte for a time t, the amount of charge (q) passed is I t. According to the law, mass of substance liberated (m) is

m α q or m = zIt

where Z is a constant for the substance being liberated called as electrochemical equivalent. Its unit is kg C-1.

The electrochemical equivalent of a substance is defined as the mass of substance liberated in electrolysis when one coulomb charge is passed through the electrolyte.

Second Law: The mass of a substance liberated at an electrode by a given amount of charge is proportional to the chemical equivalent of the substance.

If E is the chemical equivalent of a substance, from the second law

m α E