Concept:A salt bridge is a connecting device that joins the two half-cells of an electrochemical cell while maintaining ionic balance.
Explanation:An electrochemical cell consists of two separate half-cells, each containing an electrode dipped in an electrolyte solution.
The salt bridge is a U-shaped tube filled with an inert electrolyte gel, such as
KNO3​ or
KCl.
It physically connects the two half-cells so that ions can move from one solution to the other.
This ionic movement maintains electrical neutrality in both half-cells during the redox reaction.
Without the salt bridge, charge would build up in the solutions and the cell would stop producing current.
The salt bridge does not act as a cathode or an anode, because it does not undergo oxidation or reduction.
It also does not measure electrode potential, as that is the function of a voltmeter or potentiometer.
Hence, among the given options, the main function of the salt bridge is to connect the two half-cells.
Answer:Option C: To connect two half cells.