EMF is abbreviated as electromotive force which is defined as the maximum potential difference between the two electrodes of a galvanic cell.
EMF of a Galvanic cell:
Galvanic cell is one of the most important electrochemical cell. A galvanic cell has a combination of two metal rods known as electrodes. Both the electrodes are immersed in a solution that contains the combination of ions and therefore form a half cell. The half cell is connected by salt bridge and the solution in which both the electrode lies is known as electrolyte. The chemical reaction happening in this cell is known as the redox reaction. Oxidation takes place in one of the electrode that acts as an anode and reduction takes place in other electrode that acts as a cathode.
The cell notation: Some rules need to be taken care while representing an electrochemical cell.
Cathode is on the right side and anode on the left side.
The cell is represented by the rule that metals are written first and then the metal ions that are present in the electrolyte. The two needs to be separated by a vertical line. For example: Zn | Zn2+.
The molar concentration is written within the brackets as: Zn | Zn2+(1M)
If we take an example of Daniell cell, it can be represented as: Zn | Zn2+ || Cu2+ | Cu
Then cell notation is as follows:
Zn | Zn2+ (1M) || Cu2+ (1M)| Cu
Cell potential or electromotive force (EMF): It is the potential difference between electrodes in a galvanic cell and is measured in volts. It can be represented as:
Emf of the cell= Half cell potential at cathode (right side) – Half cell potential at anode (left side)
To learn more about the determination of emf of a cell using Nernst Equation, install Byju’s-The learning app.