Cheat sheet · Class 12 · CBSE · Science Chemistry

Electrochemistry cheat sheet

The whole chapter on one page: key formulas, facts and the points to remember, for quick revision before a test.

CBSE Class 12 · Chemistry

Cheat sheet

Chapter 2Electrochemistry

Anode Oxidation, Reduction Cathode — “An Ox, Red Cat”.

1. Cells

Ecell∘=Ecathode∘−Eanode∘E^\circ_{cell} = E^\circ_{cathode} - E^\circ_{anode}
ΔG∘=−nFEcell∘\Delta G^\circ = -nFE^\circ_{cell}

Galvanic cell: chemical → electrical. Salt bridge keeps neutrality.

2. Nernst Equation

E=E∘−0.059nlog⁡QE = E^\circ - \dfrac{0.059}{n}\log Q (298 K)
E∘=0.059nlog⁡KcE^\circ = \dfrac{0.059}{n}\log K_c

3. Conductance

κ=1R⋅lA\kappa = \dfrac{1}{R}\cdot\dfrac{l}{A}Λm=κc\Lambda_m = \dfrac{\kappa}{c}
Λm=Λm∘−Ac\Lambda_m = \Lambda_m^\circ - A\sqrt c (strong electrolytes)

Kohlrausch's law: Λm∘=ν+λ+∘+ν−λ−∘\Lambda_m^\circ = \nu_+\lambda_+^\circ + \nu_-\lambda_-^\circ — used for weak electrolytes and α=Λm/Λm∘\alpha = \Lambda_m/\Lambda_m^\circ.

4. Electrolysis

m=ZItm = ZItQ=ItQ = It1F=96 5001F = 96\,500 C

5. Batteries & Corrosion

  • Primary: dry cell, mercury cell.
  • Secondary: lead storage, Ni–Cd.
  • Fuel cell: H₂–O₂ (Apollo).
  • Rusting is electrochemical; prevent by galvanising, painting, sacrificial anode.

6. Key Points

  • SHE has E° = 0 V.
  • Positive E°cell ⇒ spontaneous.
  • Molar conductivity rises on dilution.
  • κ decreases on dilution.

Remember: E°cell | Nernst | Kohlrausch | Faraday's laws

Electrochemistry: questions and notes

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