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प्रश्न
How are standard electrode potentials measured?
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उत्तर
The potential difference between two single electrodes (half cells) can be measured. Therefore, a galvanic cell is constructed by connecting the provided electrode with a standard hydrogen electrode, and the potential difference between the two electrodes is observed in order to determine the electrode potential of a particular single electrode (half cell).
The observed potential difference is mathematically equivalent to the single electrode potential of the specified electrode because the electrode potential of a standard hydrogen electrode is zero.
Since the standard hydrogen electrode’s potential is zero by convention, the measured value of the potential difference is numerically identical to the half cell’s standard electrode potential, or \[\ce{E^{\circ}_{{Mn}/{Mn^{n+}}}}\].
The potential difference between the anode and the cathode in a galvanic cell in the standard state is represented by \[\ce{E^{\circ}_{cell}}\]. This is given by:
\[\ce{E^{\circ}_{cell} = E^{\circ}_{cathode} - E^{\circ}_{anode}}\]
