Answer:
A pathway by which counter ions can flow between the half-cells without the solutions in the half-cell totally mixing.
Step-by-step explanation:
Salt bridge is a link between oxidation half and reduction half of a galvanic cell.
Functions of salt bridge are:
Maintaining electrical neutrality
Preventing cell from reaching equilibrium
For creating salt bridge, a U shaped glass tube is filled with an inert electrolyte. Electrolytes used in the salt bridge generally do not reacts with the cell chemicals.
Cations and anions of the electrolytes have same ionic conductivity and hence, migrate with the same speed.
Most commonly potassium chloride, sodium chloride and potassium nitrate are used as an electrolyte in salt bridge.
Electrolyte are generally mixed with agar agar to prevent mixing of chemicals in the two half cells.