Course Content
CHAPTER 10: HALOALKANES AND HALOARENES
Topic Name 10 Haloalkanes and Haloarenes 10.1 Classification 10.2 Nomenclature 10.3 Nature of C–X Bond 10.4 Methods of Preparation of Haloalkanes 10.5 Preparation of Haloarenes 10.6 Physical Properties 10.7 Chemical Reactions
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CHAPTER 11: ALCOHOLS, PHENOLS AND ETHERS
Topic Name 11 Alcohols, Phenols and Ethers 11.1 Classification 11.2 Nomenclature 11.3 Structures of Functional Groups 11.4 Alcohols and Phenols 11.5 Some Commercially Important Alcohols 11.6 Ethers
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Class 12th Chemistry Online Class For 100% Result
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Nernst Equation

  • This equation was named after a German physicist Walther Nernst.
Class 12 Electrochemistry Notes
Class 12 Electrochemistry Notes
  • The Nernst Equation empowers the assurance of cell potential under non-standard conditions and relates the measured cell potential to the reaction quotient and permits the exact measurement of equilibrium constants.
  • Let us consider an electrochemical reaction of the following type:

aA +bB  –> cC + dD

  • Nernst equation for this can be written as follows:
  • If the circuit in Daniel cell is closed:

Zn(s) + Cu2+ (aq) →Zn2+ (aq) + Cu(s)

Class 12 Electrochemistry Notes

Problem:

Calculate the emf of the cell in which the following reaction takes place: Ni(s) + 2Ag+ (0.002 M) → Ni2+ (0.160 M) + 2Ag(s). Given that Eøcell = 1.05 V.


Electrochemical Cell and Gibbs Energy of the Reaction

Class 12 Electrochemistry Notes
Class 12 Electrochemistry Notes
  • Electrical work done (1 second) = Electrical potentialX Total charge passed
  • Passing the charges reversibly through the galvanic cell results in maximum work.
  • Reversible work done by galvanic cell = Decrease in Gibbs energy
  • Let E = Emf of the cell

           nF = Amount of charge passed

        Δr= Gibbs energy of the reaction

        ΔrG = -nFEcell

  For the reaction,

           Zn(s) + Cu2+ (aq) –> Zn2+ (aq) + Cu(s)

            [ΔrG = -2FEcell  ]

But when the equation becomes

2Zn(s) + 2Cu2+ (aq) –> 2Zn2+ (aq) + 2Cu(s)

  [ΔrG = -4FEcell  ]

Problem:

The cell in which the following reactions occurs:

Class 12 Electrochemistry Notes

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