How will you determine the standard reduction potential (E°) of an electrode experimentally?

The standard reduction potential of an electrode is determined by connecting it with a standard hydrogen electrode whose electrode potential is taken as zero.
Calculation of E° of zinc. A cell consisting of zinc electrode immersed in 1 M ZnSO₄ solution and [Standard hydrogen electrode is set up as shown.
The reading as given by voltmeter in the cell circuit is 0.76 V. This measures the E.M.F. of the cell. The electrons flow from zinc electrode to the hydrogen electrode. This means that zinc acts as an anode while hydrogen gas electrode acts as a cathode.



Since oxidation occurs at the zinc electrode, therefore, the standard electrode potential forZn²⁺|Zn half cell is –0.76 volt.
Calculation of E° of copper. A cell consisting of copper electrode immersed in 1M CuSO₄ solution and standard hydrogen electrode is set up as shown.

The reading as given by voltmeter in the cell circuit is 0.34V. This measures the E.M.F. of the cell. The electrons flow from hydrogen electrode to copper electrode. This means that hydrogen electrode acts as an anode while copper electrode acts as a cathode.

Since reduction occurs at the copper electrode, therefore, the standard electrode potential for Cu²⁺|Cu half cell is +0.34 volt.