<P> The electrode potential of each half - reaction is also known as its reduction potential E0 red, or potential when the half - reaction takes place at a cathode . The reduction potential is a measure of the tendency of the oxidizing agent to be reduced . Its value is zero for H + e → ⁄ H by definition, positive for oxidizing agents stronger than H (e.g., + 2.866 V for F) and negative for oxidizing agents that are weaker than H (e.g., − 0.763 V for Zn). </P> <P> For a redox reaction that takes place in a cell, the potential difference is: </P> <Dl> <Dd> E0 cell = E0 cathode--E0 anode </Dd> </Dl> <Dd> E0 cell = E0 cathode--E0 anode </Dd>

There can be no oxidation without a corresponding reduction