Electrode Potential

Movement of electrons are the most fundamental part electricity, when they are static they are almost of no use! We had learnt previously that electrolysis can be used to produce mobile electrons, in turn producing electricity. But how can we decide which solutions to use as electrolytes and what metals as electrodes? We cannot haphazardly put any metal any where, there is a specific order required which can be decided using the electrode potential. So let's explore more!

Standard electrode potential is defined as amount of potential developed when a certain metal is immersed in it's own solution at \(298\) K.

The unit of electrode potential measured in volts, which is the amount of energy required to move one coulomb of electrons per second through a wire of length \(103\) cm, containing \(14.45\) grams of mercury at \(0^\circ\).

EMF is the abbreviation for Electro-motive force. EMF of a cell is measured using the electrode potentials of cathode and anode. We have previously that the electrons move in an external path from the negative electrode to the positive one.

The formula to calculate the EMF is given by the formula: \[\text{EMF}=\text{Electrode potential}_{\text{cathode}} -\text{Electrode potential}_{\text{anode}}\]

One simple way to find the EMF of a reaction is to subtract the more negative value from the more positive value, giving the magnitude of EMF.

Definition and application of electrochemical series