Terminology for Galvanic Cells

The number of possible galvanic cells that could be built is almost unhmited. All of them have common features, and terminology has been devised to describe these features. The electrically conducting sites at which either oxidation or reduction take place are called electrodes. Oxidation occurs at the anode and reduction occurs at the cathode. These terms are also used for other types of electrochemical cells, too, not just for galvanic cells. 

Because there are so many possible electrochemical cells, a shorthand notation for representing their specific chemistry has been devised. This cell notation lists the metals and ions involved in the reaction. A vertical line,, denotes a phase boundary, and a double line, H, represents the salt bridge. The anode is always written on the left, and the cathode on the right  

Anode electrolyte of anode electrolyte of cathode cathode The previous example of copper and silver would be written as follows  

Once again, we see that the spectator ions are not identified in this notation. The concentration of the electrolyte is generally included, for reasons we will soon see. In the example above, we include concentrations of 1 M. These values have special meaning because they are the assigned concentrations for the standard state of an electrochemical cell. If the electrochemical half-reaction includes the production or consumption of a gas, the standard state is a pressure of 1 atm. A standard state also implies that the electrode material is in its thermodynamic standard state, which is commonly the case because most electrode materials are solids at room temperature. 

The word galvanic stems from the Italian physicist, Luig Calvani, who used frop to conduct early experiments on the role of electricity in living systems. 

---