Question 1

What is the function of a salt bridge in a galvanic cell?

Accepted Answer

The salt bridge maintains electrical neutrality in both half-cells by allowing ion migration — its cations move toward the cathode compartment and its anions toward the anode compartment. It also completes the internal circuit and minimises the liquid junction potential. Without it, charge builds up rapidly and the cell current stops.

Question 2

Do electrons pass through the salt bridge?

Accepted Answer

No. Electrons flow only through the external wire, from the anode to the cathode. The salt bridge conducts ions, not electrons. Any answer claiming electrons travel through the salt bridge or the solution is wrong in NEET.

Question 3

Why is the anode negative in a galvanic cell?

Accepted Answer

In a galvanic (voltaic) cell the reaction is spontaneous: the anode pushes electrons into the external circuit, so it behaves like the negative terminal of a battery. Hence anode = negative and cathode = positive. In an electrolytic cell the signs reverse because an external power source drives the reaction — but oxidation remains at the anode in both cell types.

Question 4

How is E°cell calculated?

Accepted Answer

E°cell = E°cathode − E°anode, using standard REDUCTION potentials for both electrodes. For the Daniell cell: (+0.34) − (−0.76) = +1.10 V. A positive E°cell means the reaction is spontaneous as written, and ΔG° = −nFE°cell with F = 96500 C/mol.

Question 5

What happens if the salt bridge is removed?

Accepted Answer

The circuit is broken internally. Charge quickly builds up in each half-cell (positive at the anode compartment from excess metal ions, negative at the cathode compartment), which halts further redox reaction and the current drops to zero almost immediately. Note that the cell potential itself does not become zero — it is the sustained current that stops.

Galvanic Cell Lab — Salt Bridge Carries Ions, Not Electrons

Practice

Learned it? Now prove it under the clock.