How do you calculate the standard electrode potential?

The standard electrode potential is calculated by measuring the voltage difference between a half-cell and a standard hydrogen electrode.

The standard electrode potential, also known as the reduction potential, is a measure of the tendency of a chemical species to acquire electrons and thereby be reduced. It is determined by comparing the potential of a half-cell (a structure that contains a conductive electrode and a surrounding conductive electrolyte separated by a naturally occurring Helmholtz double layer) to the potential of a standard hydrogen electrode (SHE), which is arbitrarily set at 0 volts.

To calculate the standard electrode potential, you need to set up a galvanic cell. This is a type of electrochemical cell that converts chemical energy into electrical energy. The cell consists of two half-cells connected by a salt bridge. One half-cell contains the electrode of interest, while the other half-cell is the standard hydrogen electrode.

The electrode of interest is connected to the positive terminal of a voltmeter, and the standard hydrogen electrode is connected to the negative terminal. The voltmeter measures the potential difference (voltage) between the two electrodes. This voltage is the standard electrode potential of the electrode of interest.

It's important to note that standard electrode potentials are measured under standard conditions, which are a temperature of 298K, a pressure of 1 atmosphere, and a concentration of 1M for all species in the solution. If the conditions are not standard, the electrode potential will be different.

The sign of the standard electrode potential indicates whether the species is likely to be reduced (gain electrons) or oxidised (lose electrons). A positive value means the species is likely to be reduced, while a negative value means it is likely to be oxidised. The larger the absolute value of the standard electrode potential, the stronger the species is as an oxidising or reducing agent.