What is Salt bridge? Write the functions of salt bridge.

Answer:

Salt bridge: A salt bridge is a U-shaped glass tube filled with a gel (agar-agar) saturated with a strong inert electrolyte such as KCl, KNO₃ or NH₄NO₃, which connects the two half-cell solutions of a galvanic cell.

Functions:

• It completes the electrical circuit by allowing ions to move between the two half-cells, without the solutions mixing.
• It maintains electrical neutrality of the two solutions: anions move towards the anode compartment and cations towards the cathode compartment, so the cell keeps working.
• It minimises the liquid junction potential between the two solutions.