Electrochemistry – Class 12 Chemistry Notes | CBSE NCERT Based

 📚 Chapter: Electrochemistry – Class 12 Chemistry Notes

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🔸 Introduction:

Electrochemistry is the study of the relationship between electricity and chemical reactions. It includes redox reactions, electrochemical cells, electrode potentials, and electrolysis.

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🔹 1. Electrochemical Cell

Converts chemical energy → electrical energy

Also called Galvanic Cell or Voltaic Cell

Example: Daniel Cell (Zn | Zn²⁺ || Cu²⁺ | Cu)

Cell Notation:

Anode (oxidation) || Cathode (reduction)

e.g., Zn | Zn²⁺ || Cu²⁺ | Cu

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🔹 2. Electrode Potential

Reduction Potential (E°red): Tendency to gain electrons

Oxidation Potential (E°ox): Tendency to lose electrons

Standard electrode potential measured under:

1 M concentration

1 atm pressure

25°C temperature

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🔹 3. EMF of Cell

E°cell = E°cathode – E°anode

If E°cell > 0 → reaction is spontaneous

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🔹 4. Nernst Equation

Used to calculate cell potential under non-standard conditions:

E = E° - \frac{0.0591}{n} \log \frac{[Products]}{[Reactants]}

Where:

E = cell potential

n = number of electrons

[ ] = concentration

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🔹 5. Electrochemical Series

A list of elements arranged in order of increasing E°red

Useful to predict oxidising and reducing strengths

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🔹 6. Electrolytic Cell

Converts electrical energy → chemical energy

Occurs during electrolysis

Example: Electrolysis of molten NaCl

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🔹 7. Electrolysis and Faraday’s Laws

First Law:

Mass ∝ charge passed

m = Z \times Q = ZIt

Second Law:

Mass of elements deposited ∝ equivalent weights

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🔹 8. Conductance of Electrolytic Solutions

Specific Conductance (κ): Conductance of 1 cm³ of solution

Molar Conductivity (Λm): Conductivity per mole

\Lambda_m = \frac{\kappa \times 1000}{M}

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🔹 9. Kohlrausch’s Law

At infinite dilution:

\Lambda_m^\infty = \lambda^+ + \lambda^-

Used to find molar conductance of weak electrolytes.

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📌 Conclusion:

Electrochemistry connects chemistry and electricity. It is crucial for batteries, co

rrosion, and electroplating industries.

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✍️ Written by: Shahid – Study with Shahid

🔗 Visit: https://shahidnotes12.blogspot.com