Notes On Measurement of Electrode Potential - CBSE Class 12 Chemistry

If the potential of a half cell is arbitrarily chosen as the standard, then the potential of the other half cell with respect to the arbitrary standard can be determined.

Arbitrarily, the standard hydrogen electrode is chosen as the standard reference electrode.

The standard hydrogen electrode consists of a platinum electrode, coated with powdered platinum.

By convention, the potential of the standard hydrogen electrode is assumed as zero volts.

The standard electrode potential of an unknown half cell is determined experimentally by combining it with the standard hydrogen electrode.

Standard electrode potentials are measured relative to the standard hydrogen electrode.

The values of standard electrode potentials of some electrodes are,

The emf of a cell is calculated as the difference of the potential of the two electrodes.

Standard oxidation potential = - (Standard reduction potential).

The half-reaction with the more positive electrode potential will undergo reduction. The half-reaction with the more negative electrode potential will undergo oxidation.

Ecell can be calculated by adding the oxidation and the reduction potentials.

As the value of standard potential decreases, half-reactions have a greater tendency to oxidise.

Summary

If the potential of a half cell is arbitrarily chosen as the standard, then the potential of the other half cell with respect to the arbitrary standard can be determined.

Arbitrarily, the standard hydrogen electrode is chosen as the standard reference electrode.

The standard hydrogen electrode consists of a platinum electrode, coated with powdered platinum.

By convention, the potential of the standard hydrogen electrode is assumed as zero volts.

The standard electrode potential of an unknown half cell is determined experimentally by combining it with the standard hydrogen electrode.

Standard electrode potentials are measured relative to the standard hydrogen electrode.

The values of standard electrode potentials of some electrodes are,

The emf of a cell is calculated as the difference of the potential of the two electrodes.

Standard oxidation potential = - (Standard reduction potential).

The half-reaction with the more positive electrode potential will undergo reduction. The half-reaction with the more negative electrode potential will undergo oxidation.

Ecell can be calculated by adding the oxidation and the reduction potentials.

As the value of standard potential decreases, half-reactions have a greater tendency to oxidise.

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