Define : Standard electrode potential.

The standard electrode potential, often denoted as E° or E°red, is a measure of the tendency of a half-cell (electrode) to undergo reduction (gain of electrons) or oxidation (loss of electrons) under standard conditions. Standard conditions usually refer to a temperature of 25°C (298 K), a pressure of 1 atmosphere, and concentrations of 1 M for all species in solution.

The standard electrode potential is expressed in volts (V) and is a quantitative representation of the electrochemical potential difference between a specific electrode and a standard reference electrode (usually the standard hydrogen electrode, SHE) when they are connected through an external circuit and allowed to reach equilibrium. The standard hydrogen electrode is assigned a standard electrode potential of 0 volts by convention.

The standard electrode potential provides insights into the relative reactivity of different half-reactions in electrochemical cells. A positive standard electrode potential indicates a tendency for reduction to occur at that electrode, while a negative value suggests a tendency for oxidation. The larger the magnitude of the standard electrode potential, the stronger the tendency for the respective redox reaction to occur.

It's important to note that the standard electrode potential is a thermodynamic property and doesn't directly indicate the rate of the redox reaction, which is influenced by kinetic factors and other conditions.