standard electrode

A standard electrode, also called a reference electrode, a half-cell combined with another half-cell and used as a reference. The basic standard cell is the hydrogen electrode – a platinum electrode immersed in a molar solution (see mole) of hydrogen ions and covered with an absorbent layer of platinum black, over which is bubbled molecular hydrogen at standard ambient temperature and pressure (SATP). This is taken to have an electrode potential of zero.


If the potential of a standard half-cell is assumed to be zero, then the experimentally measured difference in potential between the standard and a second half-cell is the relative potential of that second half-cell.


standard hydrogen electrode