Scientists have chosen an arbitrary electrode to serve as a reference to determine the standard cell potential

Hydrogen electrode.

Explanation:

A Standard hydrogen electrode (SHE), is an electrode that scientists apply for reference on all half-cell potential reactions. It´s the foundation needed to calculate cell potentials utilizing different concentrations or electrodes. The value of the standard electrode potential is zero. The potentials of other electrodes are measured with that of the standard hydrogen electrode at an identical temperature.

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