A Concentration Cell is a unique electrochemical cell where the two half-cells are chemically identical but have different concentrations of the electrolyte.

• Structure: Both the anode and cathode are made of the same metal immersed in solutions of the same salt but at different concentrations ($C_1$ and $C_2$).
• EMF ($E_{cell}$): Driven purely by the entropy of dilution. The standard cell potential ($E^{\circ }$) is zero because the electrodes are identical.
• Reaction occurs as ions move from higher concentration to lower concentration symbolically through electron flow.