Concept:Just as sea level is assigned an arbitrary altitude of 0 meters to measure the height of mountains, electrochemistry requires a "sea level" to measure standard voltages.
Solution:- The Standard Hydrogen Electrode (SHE) consists of platinum submerged in \( 1 \text{ M} \) \( H^+ \) solution, with \( H_2 \) gas bubbled at \( 1 \text{ atm} \).
- By universal international convention, the thermodynamic value for the reduction potential (and oxidation potential) of this specific half-cell is set exactly to Zero Volts (\( 0.00 \text{ V} \)) at all temperatures.
Why other options are incorrect:Values like \( +1 \) or \( -1 \) are not used. A baseline of exactly zero allows for a mathematically simple reference scale featuring positive and negative values.
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