Standard Hydrogen Electrode and Potentials

8 Standard Hydrogen and Other Reference Electrodes 2.8.1 Standard Hydrogen Electrode and Potentials 

The standard hydrogen electrode (SHE), also referred to as normal hydrogen electrode, is the universal reference for reporting relative half-cell potentials. The SHE could be used as either an anode or a cathode depending upon the nature of the half-cell it is used with. SHE is based on the redox half-cell  

Its absolute electrode potential is estimated to be 4.44 0.02 V at 25°C. Potentials of any other electrodes are compared with that of the SHE at the same temperature. 

To find the reduction potentials for other electrodes, the cells are formed by connecting the SHE as the anode and the other half-cell as the cathode. Since its potential is assigned the value of 0.000 V, all of the potential difference measured experimentally is attributed to the other test electrode. In Table 2.2, the standard electrode potentials at 25°C for various electrodes are listed. 

As can be seen from Table 2.2, F2 is a stronger oxidant than while Cu + is a weaker oxidant than Ce +. Similarly, Ag is a stronger reductant than Au and Co + is a weaker reductant than Sn +. 

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