Final answer:
The standard electrode potential of a half-cell, notated E°, is the potential difference when that half-cell functions as a cathode connected to an SHE at standard-state conditions, and it indicates the cell's relative oxidizing power.
Step-by-step explanation:
The standard electrode potential of a half-cell (E°) is defined as the potential difference measured when a half-cell is connected to a standard hydrogen electrode (SHE) under standard-state conditions. The SHE is assigned a potential of exactly 0 V, functioning as a universal reference point.
When a half-cell X operates under these conditions (1 M concentration, 1 bar pressure, 298 K temperature), its potential is the standard electrode potential, denoted as E°x. These standard electrode potentials can be arranged to show the relative oxidizing strengths of different half-reactions, with larger (more positive) E°x values indicating stronger oxidants. Hence, the standard cell potential (E°cell) is computed using the formula E°cell = E°cathode - E°anode, which reflects the spontaneity of the electrochemical reaction.