Electrolysis and first Law of Faraday

Electrolysis and Faraday’s First Law

Electrolysis is a chemical process where electrical energy is used to drive a non-spontaneous chemical reaction. It generally refers to breaking down an electrolyte into its basic components using an electric current.

What Happens During Electrolysis?

In the process of electrolysis, the ions within the electrolyte migrate toward their respective electrodes. Positive ions (cations) migrate towards the cathode and gain electrons (reduction), while negative ions (anions) move to the anode and lose electrons (oxidation).

Applications of Electrolysis

• Electroplating of metals
• Extraction of metals from ores (e.g., aluminum from bauxite)
• Purification of metals (e.g., copper)

Faraday’s First Law of Electrolysis

According to Faraday’s First Law:

“The mass of a substance deposited or liberated at an electrode is directly proportional to the quantity of electricity passed through the electrolyte.”

The law can be represented mathematically as:

m = Z × Q

Where:

• m = mass of the substance deposited (in grams)
• Z = electrochemical equivalent (in g/C)
• Q = total electric charge passed (in coulombs)

Relation with Current and Time

Electric charge (Q) is obtained by the product of current and the duration for which it flows:

Q = I × t

Where:

• I = current in amperes (A)
• t = time in seconds (s)

Faraday’s First Law provides a clear relationship between electricity and the amount of chemical change. It forms the basis of quantitative electrolysis and is fundamental to understanding how electrical energy causes chemical transformations.