Salt Bridge
A conducting connection between the two half-cells of a galvanic cell that completes the circuit and maintains electrical neutrality.
Unit
Dimensionless
In depth
As the reaction proceeds, positive charge would build up in the anode compartment and negative charge in the cathode compartment, halting the cell within moments. The salt bridge supplies ions that migrate to cancel these imbalances, and its electrolyte is chosen so that neither ion reacts.
Examples in the real world
An inverted U-tube of potassium nitrate in agar jelly; a strip of filter paper soaked in KCl solution.