Notes On Quantitative Aspect Of Electrolysis - CBSE Class 12 Chemistry

Electrolytic cells require electrical energy to drive a chemical reaction. Thus electrolytic cells are non-spontaneous and have negative Ecell values.

In galvanic cells, the anode is considered to be the negative electrode and reactions are spontaneous. The cell potential is always positive and the Gibbs free energy is negative.

In electrolytic cells, the cathode is considered to be the negative electrode and the reactions are non-spontaneous. The cell potential is negative and Gibbs free energy has positive value for electrolytic cells.

The important application of electrolysis is electrolytic refining.

Michael Faraday was the first scientist to quantitatively study electrolysis.

Faraday's first law states that the amount of chemical reaction that occurs at any electrode during electrolysis is directly proportional to the quantity of electricity passed through the electrolyte.

        m (Mass of element deposited at electrode) ∝ Q (Amount of electricity passed through cell)

Faraday's second law states that the amounts of different substances produced by the same amount of electricity passing through the electrolytic solution are proportional to their equivalent masses.

m1/E1 = m1/E2

The amount of charge passed through the cell = Current (I)* Time (t)

Q =It

Coulombs = Amphere * Seconds

The Faraday is the charge on one mole of electrons.

1Faraday = 96,500 coulombs/mole.

The electrolysis of binary molten salts gives elemental products.

The products of electrolysis of aqueous salt solutions can be predicted on the basis of the relative ease of oxidation and reduction of the ions present and water.

Summary

Electrolytic cells require electrical energy to drive a chemical reaction. Thus electrolytic cells are non-spontaneous and have negative Ecell values.

In galvanic cells, the anode is considered to be the negative electrode and reactions are spontaneous. The cell potential is always positive and the Gibbs free energy is negative.

In electrolytic cells, the cathode is considered to be the negative electrode and the reactions are non-spontaneous. The cell potential is negative and Gibbs free energy has positive value for electrolytic cells.

The important application of electrolysis is electrolytic refining.

Michael Faraday was the first scientist to quantitatively study electrolysis.

Faraday's first law states that the amount of chemical reaction that occurs at any electrode during electrolysis is directly proportional to the quantity of electricity passed through the electrolyte.

        m (Mass of element deposited at electrode) ∝ Q (Amount of electricity passed through cell)

Faraday's second law states that the amounts of different substances produced by the same amount of electricity passing through the electrolytic solution are proportional to their equivalent masses.

m1/E1 = m1/E2

The amount of charge passed through the cell = Current (I)* Time (t)

Q =It

Coulombs = Amphere * Seconds

The Faraday is the charge on one mole of electrons.

1Faraday = 96,500 coulombs/mole.

The electrolysis of binary molten salts gives elemental products.

The products of electrolysis of aqueous salt solutions can be predicted on the basis of the relative ease of oxidation and reduction of the ions present and water.

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